Pre-labor symptoms??

I started having mensural cramps yesterday and lower back pain, nausea and vomiting as well. But it went away and in the middle of the night the cramps started again and nausea and this time I had a bad headache, I took some Tylenol and finally fell back asleep after 2 hours. This morning it’s starting all over again, they hurt and it feels like a heavy period. Just achy and when the cramps start it hurts 😩 also I’m having a increase of white discharge this morning. I’m drinking a lot of water so I know it’s not uti. Anyone else experience these symptoms before going into labor? 3rd pregnancy, due December 19th!!