Today i felt really nauseous this evening and had to run to the bathroom and vomit i had unprotected sex 3 days ago could this have anything to do with it? could it be a early pregnancy sign? could it be the hormones from pregnancy if i am pregnant?

3 days is too early: It can be hard to tell if a woman is pregnant because some of the symptoms seen in early pregnancy can also happen in non-pregnant women. A urine pregnancy test gives a reliable result if done correctly. One can test about 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a period. An Ob-Gyn doctor can evaluate any persistent or worrisome symptoms.