Opinions please

Soooooo my boyfriend & I had sex almost a week ago & he came in me for the first time ever. He swears I'm pregnant. I got my period a week early & started getting nauseous & sick like but without the side effects of an actual flu like thing. We used a product called Encare which is a thing that dissolve into a spermicide & sponge like effect but he said it was a huge load & that he knows for sure I'm pregnant. When would be the best time to test. (Still on my 'period' for about 2 days now MAYBE 3)