What Causes Stomach Cramping And Bloating With Nausea?

Hi, may I answer your health queries right now ? hello, I am 19 and recently I found out that I had a uti so I went to the doctor for that... I had unprotected sex about 17 days ago and my period was due about 3 days ago.... Last night I took a pregnancy test and it came out negative... my stomach feels slightly crampy and bloated and I feel like I am nauseous, but I usually feel that way before my period what do you suggest I do?