Hello,
Sperms lose their effectiveness when deposited in air outside the vagina. Chances of pregnancy are less because sperms need to travel up the fallopian tubes to cause pregnancy. You can take post coital pills within 5 days of unprotected intercourse but preferably between 72 hours of having intercourse.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
If your worried take plan b. The pull out method does not work!