How likely is it to get a positive pregnancy test 8 days after having sex?

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Im in a bit of a situation. Im 22 weeks pregnant and trying to figure out whos my baby’s dad is as bad as that sound but its driving me nuts. Im just wondering if its even possible to get a positive pregnancy test after 8 days of having sex? I had sex on monday and the next tuesday it came back positive. Im really hoping its not possible but if can help me out id really appreciate it. Thanks everyone.

I think 8 days is too early for a positive.
Not very likely. Only a blood test at the doctor would give positive results that soon. You need to have a dna test when the baby is born.
your question make me crazy too.i don’t think so may be you had sex before,if you ovulate at the time you had may be you get the positive if your luteal Phase is short.yes its possible if your luteal phase is short length
I would say less than a 5% chance. I will explain why though. After conception-the egg and sperm meeting to create an embryo,it takes 5-7 days for that embryo to travel down the fallopian tube and then implant into the uterine wall. Then and only then does your body start making HcG. Your hormone levels would not be near high enough to get a positive.
I would wait a few days.