Cramping everyday on BC pill

Hi! So I’m new to the pill. I’m going on my third week on it. Shortly after starting, I started experiencing cramps randomly throughout the day everyday, lasting about 15 seconds or something each time. Kinda feels like it’s getting worse, the pain. I was scared last Monday because the night before I had unexpected unprotected sex(he pulled out) so I took the generic plan b pill at Walmart and still taking my BC pill on time. After that, the pain of the cramps got worse. Still last for a short period of time. Is it because I took that extra pill..??