The first day of my last period was March 31st. We have sex on the weekends when we see each other. About 2 weeks ago I spotted, light pink with a couple streaks of red about 2 days after we were together. About a week and a half ago my breasts became extremely tender and more firm. My period is always regular. Sometimes a day early or late. I spotted today as well. Light pink. No cramps or anything. My breasts are still extremely tender and firm. I took a test a couple days ago and it was negative. We did have sex on my most fertile days. Any ideas?