lower back cramps

Aubrey🌺
So ftm and 40 weeks, obviously anxiously looking at anything as a sign at this point. I've been having a pain in my lower back like a cramp. It only last a minute at most but they are becoming more frequent. The pain level has stayed the same though. Does anyone have an idea of what this could be? I thought nothing of it when it started but now it happens a lot more often.