4 Weeks Pregnant: Implantation and Confirmation 8


4 weeks pregnant is an exciting time. Why? Well, because this is the first week you may technically be pregnant and even be able to confirm that pregnancy. If you are pregnant, your baby will reach its destination in your uterus sometime this week and set up shop. This process is called implantation.

How do you know if your baby has implanted?

You may not, some women have no implantation symptoms. Some signs that implantation may have occurred include:

-About a third of women experience implantation bleeding. This is often very light bleeding (possibly as little as 1 drop or faint pink on the toilet paper when you wipe) that occurs around 6 to 12 days after intercourse or ovulation. The timing can make it tricky to tell implantation bleeding from a period or pre-period spotting.

-Occasionally women report cramping or a “pinching” feeling in their uterus around implantation.

-Those who are charting their basal body temperature may also notice a sudden drop followed by a rise in temperature at implantation.

Pregnancy Symptoms at 4 weeks:

Keep in mind that symptoms of pregnancy don’t begin immediately after implantation. Pregnancy symptoms are caused by hormones associated with pregnancy which only begin to rise after implantation. Some women do report pregnancy symptoms very early, but this is because progesterone is present before implantation, and progesterone is to blame for many early pregnancy signs. You can take a quiz or read more about early pregnancy signs here.

Ok, lets assume your baby implanted, congratulations! What happens next?4 weeks pregnant

Your body immediately begins to produce the hormone hCG after your baby implants. This hormone tells the corpus luteum to keep making progesterone, so you don’t get your period. It’s also what will cause a pregnancy test to become positive in the coming days. The blastocyst (remember that’s what the fertilized egg is called once it implants) begins to split creating your baby from some cells and chorionic villi, or hair like projections that will later form your placenta. These projections help anchor your baby to your uterus. Fluid also begins to build, and a yolk-like sac begins to form. This yolk will nourish your baby until the placenta is complete. At the moment, this whole collection of cells is somewhere between the size of a pinhead and a poppy seed, but the speed at which your baby is going to grow from here on out is impressive.

Can you confirm your pregnancy at 4 weeks pregnant?

By the end of week four, hormone levels are most likely high enough to receive a definitive yes or no on an early result home pregnancy test, though waiting until week 5 can be a more sure-thing. Remember, that hCG levels at least double every 48 hours in a normal pregnancy, so waiting even one day later can make a huge difference between no line, a barely visible line, and an unquestionable yes. Be patient.


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8 thoughts on “4 Weeks Pregnant: Implantation and Confirmation

  • Star

    Had strange bleeding I know I posted before, but I hope you can read this and help me because I did experience some weird bleeding this month.Anyway like I said I had unprotected sex a month ago on January 1st which didn’t last long to pushing him away. I was still scared of precum so I took a generic form of plan B. I then bled a week after on January 14th which seemed like a normal period lasting the normal 6 days. On February 10th I went to my OBGYN for a pelvic exam and said I wasn’t pregnant unless I had sex in that month which I have not. Not since the horrible situation in January. It is now February 15th 45 days after the intercourse situation. I thought I was experiencing my period. instead it is brown blood with red and one clot in the toilet and bleeding was light and lasted all day, till night time it just suddenly stopped. I am worried I thought I wasn’t pregnant due to what my doctor said, but now I had that strange bleeding was that implantation or something else because it literally has been 45 days since intercourse so 6 weeks. I hope someone can answer this I am freaking out.

    • unwirklich admin

      Plan B will often cause irregular bleeding for a month or two as it’s hormone based and upsets hormone levels. If you saw a provider feb 10th and weren’t pregnant, that’s a finding you can trust still a week later. :) Implantation can take place no later than about 14 days after intercourse.

  • Amy

    Had sex the week of may 7th-13th am on birth control but no the best at taking it. Got my period on time but it was very light and off and on. Haven’t been feeling the greatest but I’m also a freak of anxiety and look up symptoms on google and stories that I probably shouldn’t. I hadn’t had interviews up until two days ago cause I waited to be on birth control for two weeks at the same time & it occurred in the shower and he pulled out. I took a pregnancy test today because I’m absolutely convinced I am, it’s 6/5/17 and it said NO. Relieved for that but now worried about the last time, it’s only been two days and I’m due for my period next Tuesday. Feel like my boobs are sore and also constipated with heavier than usual discharge. Any idea if it’s in my head or or if I could actually be pregnant ?

    • unwirklich admin

      You won’t have pregnancy symptoms before a missed period (explanation here) and if the latest sexual act was the 13th, a test should have been accurate anytime after about the 27th (2 weeks) making the 5th well into the accuracy range. My bet here is not pregnant.

      • Amy

        I also had it the 3rd of this month in the shower with him pulling out and me taking my birth control on time all month, is there a good chance I still could get pregnant by that? I’ve been super constipated and very stressed out. My discharge has been so funky and I can’t tell if I’ve spotted or not. :( it was so dumb

        • unwirklich admin

          The chance of pregnancy with proper birth control use is around 1-3% all by itself, and if the pull out method is done properly it’s effectiveness is rated at about 75% by most sources, higher if there was urination between any previous ejaculation and the act. Between the two, it’s very, very, unlikely. I would try not to stress it, wait and see if your period comes. Remember that normal period variance is +/-3 days. If it’s late more than 3 days, retest.

  • Mi640616

    I had unprotected sex on December 20th, about 2.5 weeks after my last period (which ended on the 1st of December), but I also experienced light bleeding for 4 days right before having sex (the 15th-18th). It was weird enough to make me think my period had come early, so I logged it as such. Now I am unsure that it was my period because I have been having gastrointestinal issues and have experienced acne as well as very sore breasts for the past two weeks. I’ve also been peeing and eating enough for what seems like a 10 people. I feel that it may be too early to take a test and get accurate results since my “logged” period isn’t due until Jan. 22nd. I would love to hear your thoughts on the chances of being pregnant.

    • Life with Gremlins admin

      As a general rule, if it’s too early for a test, it’s too early for symptoms. Pregnancy tests pick up very low levels of the first pregnancy hormone released. You can have pregnancy-like symptoms before (or without) being pregnant. Most of those symptoms are just a result of imbalanced hormones (high progesterone is a big one). With irregular bleeding mid-cycle, in my opinion an imbalance is more likely than pregnancy.