FTM start of labor or no?

I started having mild/ moderate contractions last night around 11pm... they were frequent but not consistent. Then they tappered off after about 10 contractions. I was able to sleep for about 2 hours. Then I started contracting again, this time more intense, but still inconsistent. They were painful. After about an hour or so of that they again tappered off and I was able to sleep. When I woke up this am I woke up with the worst period cramps, and it feels like I need to poop but nothing has come out yet. I also have a headache and slightly nauseous. Is this the beginnings of labor? 37+4