Start of labor? 39 weeks with period like cramps...

FTM. For the last 3 days, I’ve had almost constant period-like cramps. Very mild. I woke up an hour ago with stronger pain in my lower abdomen. I still have the constant period pain, but 3 times in the last hour, it’s gotten stronger, then stops again. TMI, but it almost feels like I have to poop when it gets stronger. It’s only my lower abdomen/stomach too. Not my whole belly. Are these contractions? Also, can you go into labor without loosing your mucus plug?