almost 39 weeks and pain

I'll be 39 weeks tomorrow and today I woke up with severe pain on my left side it feels like a pulled muscle but it's also making my lower stomach right too. Not sure if thisnisnthe start of contractions as I had something similar happen on Saturday night and I ended up going to labor and delivery and I was having contractions but not enough so they sent me home. It's really hard to walk with this pain. Anyone think this is the start?