Possible pregnancy symptoms

Patient: About a month ago I had sex with my boyfriend but the condom broke so the day after I took a plan B pill. A couple of days after that we had unprotected sex but 3 days after that I got my period. It was somewhat weird because it came about a week earlier than normal but I figured it was because of the plan B and it was definitely my period since it lasted for around 4 days. Now I am feeling pressure in my stomach and I am constantly burping and feeling random pains. I am not sure if I am just having digestive issues or if it is somehow possible that I could be pregnant because I have looked up my symptoms and I’m not sure if it is possible that I can be pregnant or if I am just freaking out about everything.

Symptoms: Belching, gas, feeling of pressure/fullness in stomach, slight lower back pain, slight bleeding in gums