I went through this too with both pregnancies
It's most likely stretching unless you're bleeding I wouldn't worry. Sometimes I over do it chasing my son or it's just time for another growth spurt.
If you feel really awful call your Dr but I'd think you're ok
If you overdid it, it might just be sore. No bleeding? Then you are probably fine. But if it gets worse call your doctor. Or you could take some Tylenol?