I had unprotcted sex 2 days ago and the morning after I felt really nausceaous and had cramps in my stomach and the nausea came back today.?

Find symptom's cause. Nausea/vomiting may be gi-related (food poisoning, peptic disease, gastroparesis, due to biliary & pancreatic disease, gas/bloat syndrome, small bowel problems). Consider "central" causes: motion sickness, vertigo, migraine headache, brain problems (some very serious). Also, rule out infection (? Urinary tract), medication side effects, pregnancy, & even reaction to stress. Find & treat cause.