I’m scared I’m late

I took the emergency pill on April 22nd and then had my last period on May 1st but then I had intercourse again on May 10th and May 18th, he used a condom. But my period should have started on the 29th of May. I’m late 6 days and I’m starting to get nervous, maybe something went wrong with the condom and we didn’t notice. I’ve never been a regular or I wouldn’t know cause I barely started tracking my period. I’ve been having constipation, nausea, and just today morning my stomach hurt terribly. I’m so scared and stressed to be pregnant. I don’t know if it’s the emergency pill I took on April 22nd that’s causing the lateness. I hope so. Someone knows what’s going on?