+OPK 10 DPO AF due 10/19/15

I have been having extremely painful boobs since approx 2 DPO. The last 5 have felt similar to how it feels when nursing and you "let down" on the sides/armpits. I took an opk yesterday  9 DPO got a faint line/ -opk. Took one today and it appears positive or at least noticeably darker than yesterday. Took an hpt and it was negative. Also have been having round ligament pain when I sneeze or get up too fast. Something I have never experienced before. Top is today bottom is yesterday. Thoughts?