Please reply. Seriously confused. Need advice

I'm 36 weeks almost 37 weeks pregnant.

Latley I've been super nauseous, I get serve head aches, my visions off by alot, and i keep having upper back pain mostly on the right side, bad diarrhea and gas, completely fatigued, super bad heartburn, and just don't feel right in general. Is there any cause for this..? Should I be worried..? Or is it just my body preparing for labour?