Scared and paranoid

Megan
Hi ladies I need some help... I have had sex with my boyfriend twice now, both times using protection. After the first time I had my period and was fine. This time about two days after it felt like I was getting my period but I wasn't, and it's due in a week or so but since I have been feeling kinda nauseas and light headed. I've had aches and pains in my kidney area and lower back and today I am stuck in bed with a migraine. My boyfriend has been tested for STIs and he hasn't got any. But I fear that I am pregnant and don't know what to think. Although we used protection we did other things afterwards and I could have been on his fingers... I don't know... Opinions?