Can u please help me . is this pregnancy or not .?

Well you might be stressing about it and when you stress it causes you not to get your period i suggest that if by the end of today you don't get your period you take a pregnancy test. It's too early to begin getting pregnancy symptoms i believe it's all in your head. Don't worry about it try to relax, but remember if you have unprotected sex there's always a huge probability of you becoming pregnant just make sure to use a condom next time or go on the pill:)