Possibly going into labor. Need advice

I'm exactly 35 weeks today and since yesteday I have been having period cramps but I think they are contractions. They don't seem very consistent though. I have had a few that were about 5 minutes apart but I have also had some that were a few hours apart. My last one was a little over an hour ago. Also this might be tmi but last night I sneezed and I soaked through my underwear and ever since then I feel like I'm wet constantly even right after I pee. I have an appointment next week but I'm not sure if I should wait until then.