Hi. My question is if 4 weeks difference in pregnancy is a lot? For example, is 13 weeks really a big difference to 17 weeks? See, my period has always been regular. Its just sometimes it decides to come earlier in the month or at the end, but I still get it every month no matter what. Well on sept 21 I had intercourse with no condom. However, me & the guy didn't recall him shooting it in me. I remember him taking it out before he did but putting it back after. On October 5 I decided to take a pregnancy test (not a home pregnant test) & it came out negative & I got my period that same day. Now, since I started my period on oct 5, I would be most fertile around probably the 15-20? & that time, I had intercourse just about everyday that week (& he did shoot it in) but this is not with the same guy I did it with on sept 21. I then once again took a pregnant test I believe on November 8 (with a home pregnant test) & it came out positive. So just to clear my head, who is most likely the father? I only did it with the guy once on sept 21 but the other guy That I had intercourse with for the whole week I was most fertile with, we did it everyday w/ him shooting in every time.

Most likely the second guy simply because you had a period after the first one. However, when the first guy withdrew for ejaculation, and then reinserted, he made one of the biggest mistakes people do by thinking there would be no sperm present... which is not the case. Pregnancy can, and does, happen in that situation.

What has been seen on ultrasound? How far along are you though to be? If you had an ultrasound early on, that can give you a fairly good idea of when you most likely conceived. Four weeks in terms of a baby's development makes a tremendous difference.

Im 31 weeks now. My first ultrasound was on week 13. & in that week, the baby's head didn't look as developed as it should be if she was 17 weeks. At my ultrasound, her head was still half the size of her body, which is normal at week 13. I also asked for her measurements & I looked it up on the apps I have & also online & it also measured up to be 13 weeks. I forgot to mention that the guy I had sex with on sept 21, I took plan b a day after. & we only did it once versus the other guy that I did it with everyday the week I was most fertile on & he shooted it in every time.

Most dates for conception are fairly good give or take about 2 weeks, normally 4 weeks difference will be able to determine

@Fr_Chuck I'm sorry, I didn't understand what you were saying.

Ultrasound, while not always exact, will be the best tool early on to date a pregnancy. If baby was measuring at about 13 weeks, then you would have been around that. Fr_Chuck was stating that it can be off a bit, but not by 4 weeks. That would show too big of a difference in baby's development and measurements.

@DoulaLC okay thank you. You just basically took so much weight off my chest right now. I was always thinking that too, that if it was 4 weeks more than I thought, they would've seen the difference.