13 недель беременности: тянущие боли, похожие на менструальные — это нормально?

I'm 13 weeks and 3 days pregnant. I've had cramping that is like period cramping on and off for the past 3 days. It doesn't last for that long but when it does it feels like period cramps. Do you believe it's just normal stretching pains? I'm trying not to freak out and constantly worry my next appointment is next Wednesday the 4th. Thanks in advance.