Early Pregnancy Symptoms?

So, I had sex with my boyfriend the day before my period last month. Some say it isn't possible to conceive before your period. Some say it is. But, my period was also early.

I'm going to test this weekend to be sure, but what are some early pregnancy symptoms? Because since this, I've been nauseous, my stomach has been bothering me, I've been more hungry, and I've gained weight.