On 8/12/19 and 8/17/19 my boyfriend and I had unprotected sex during my fertile window then we had unprotected sex again 8/23/19. All three times he pulled out so he didn't finish inside of me. I'm almost 99% sure he had precum on his penis all three times. I'm also not on any bc and I didn't take plan b. We used to have unprotected sex a lot about a year ago and I never got pregnant. I honestly want to be pregnant and I've been having heartburn, tiny bit of nausea, I've been cramping a little bit, and my nipples have been reallllly sore. My period is supposed to be coming on the 31st so I don't know if it's just period symptoms and I don't want to get my hopes up. Do you think I could be pregnant?

EDIT: so when I got home I realized that there was like this light brown discharge in my underwear. I'm pretty sure it stopped. Could it be implantation bleeding????