I think I'm pregnant

I'm supposed to get my period in four days. Every month my PMS is pretty consistent. I'm a little irritable, my boobs get sore, and I get pretty bad cramps. For the last three days I have been an unbearable person to be around. I've either been so sad that I can't stop crying for more than five minutes, or so angry that I can't think clearly. I'm usually pretty rational but everything feels like a direct and calculated attack on me. If my boyfriend doesn't text me back I feel like it means he doesn't love me and I get so insufferable that I can't be around people. I'm usually not like that. Today I've been really nauseous and the last few days I noticed a lot of white discharge. More than I'm used to this time in my cycle. I know my boyfriend and I had unprotected sex the day before I ovulated and he pulled out. I feel like this is way worse than just PMS though.