Hi and welcome to the site. My name is***** hope I'm able to provide some helpful medical information for you today.
It sounds quite low. Sperm can survive for up to 3-5 days but that would require that there was some sperm inside the vagina
. Studies on pre-cum are mixed, some showing no sperm possible while others confirm presence of sperm.
If you're concerned, it may be best to take a morning after pill such as Plan B. It works well if taken within 72 hours of the event. It works better the sooner it's taken.
It works by delaying ovulation
if taken right before ovulation. There are other mechanisms by thickening the mucous in the fallopian tubes
to prevent the egg and sperm getting together as well as making the lining unsuitable for an embryo
Taking Plan B will cause irregular cycle for up to 2 months after taking. The next period is commonly late, or there may be bleeding a few days after taking it, or both can happen.
No matter what happens with the bleeding pattern. Do a home urine pregnancy test
in 14 days after the sex. Use the first urine of the morning to prevent false negatives.
The risk of pregnancy
sounds quite low but taking Plan B may be worth the extra peace of mind.
I hope this was helpful. Please reply if I can clarify anything.