Nausea, Throwing up, Ovulating with protected sex days ago

Hello, I'm dealing with heavy nausea and throwing up during my time with ovulation. I had my period on Nov 7th and ended around Nov 11th. which was a very very heavy bleeding... I had protected sex with my boyfriend the day after and as the days went on I had protected sex Nov 17th. We always check the condom after and wash our hands. I started feeling nausea and threw up the morming of Nov 20th with SEVERE pains... laying on the floor pains. (note i was heavily heavily stressed the night before with a serious career interview in the morning) After some time I started feeling better. A few days went by and thanksgiving I threw up, severe pains, light headed and felt like I was going to pass out. (thanksgiving was another extremely stressful day)

I've been experiencing lower back pain since my period ended and the throwing up started right up before my ovulation.

I've had a history where my periods are very painful when I'm sexually active during the month.... 

I'm wssnot sure if this is simply a stomach bug, virus , anxiety or pregnancy symptoms. this seems a BIT early for pregnancy symptoms. 

I have a extremly stressed household and life... I feel like this could be stressed induced as well.

Getting a test soon if this continues... any advice?