31weeks and 2days pregnant an is having more white discharge, vagina and rectum pressure on and off, low back pain by my tailbone what's going on?

Pregnancy. The pressure you describe is from the extra weight you are carrying from the pregnancy. Might want to get ultrasound to make sure baby position is normal. You need to see OB anyway about the discharge which could be anything from normal to a yeast infection.
Please call your OB. Now! u amay be trying to go into premature labor, if you were my pt i would send u straight to l;d to make sure u are not because if u are and u and the baby are ok then the labor needs to be stopped and any further ?S like this should always be directed to your OB before u ask here.