might be pregnant

A few days ago I started noticing my breasts being sore. They look huge, are squishy, and my nipples are ultra sensitive. My bf and I had unprotected sex about a week ago, but I'm on nexplanon (for 2 yrs). The morning after sex I noticed a little bit of blood when I wiped.  I've been pooping with an upset stomach every morning the past four mornings, and that usually doesn't happen. I've been having super tiny cramps and yesterday there was a little bit of white discharge in my underwear. I'm not due for my period for another week and a half so I don't know what to do. Can someone help explain this to me??