My boyfriend and I had unprotected sex and used the pull out method, could I be pregnant?

On June 5th around 2 A.M. my boyfriend and I had unprotected sex using the pull out method and he said that he ejaculated a small amount inside of me. The same day I started getting slight pang around my lower left abdomen and it was only a pang, did not last long and was only noticeable not really painful, this was nothing like my usual menstrual cramps, which i usually start to get days before my period (I have had no such cramps). My last period was on May 12th and I have on average 7 day periods, therefore my fertile period is "supposedly" longer. Then on the 6th I started getting those pangs again in the same spot, mixed in with being extremely tired. On the 7th I started having another pang sort of like it, except it was on my lower right abdomen and I had lower back pains as well, all of which were tolerable. I was also very moody and would get upset at the dumbest things. On the 8th I woke up after over 10 hours of sleep, still extremely tired, all i wanted was to sleep. I have to keep going to the bathroom (pee) and I eat nonstop, which is something I never do. I was also very moody today as well, and was so tired. I was supposed to get my period today...could I get pregnant even if I had sex so close to my period if my fertile stage is longer? what could these pains be? implantation? I read implantation can occur as early as three days or a few days after ovulation. When is the earliest I can take a home pregnancy test? Can I be pregnant?