I had sex with my gf sunday. her period starts next week. i peed before. i pent rated but shortly after we put in spermicidal foam. can she be prego?

Maybe: Couples who have sex tend to make babies. That's how we humans are designed (so we don't go extinct). Anyway, a home urine pregnancy test gives a reliable result 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon.