Advice please

Jessica • My name is Jessica. I am married. We have a 9year old son and a daughter who is 2!
So my AF is going to be here may 1st. I was going to wait until next week to test but I couldn't wait :) so yesterday I got a BFN. But for the last couple of day my stomach has been feeling horrible. I vomited onces today and stomach still feels gross. Not sure what to do or think. Can anyone give me some advice?