Implantation or..?

So around 1 am this morning I got up to pee and when I wiped I had a little bit of pinkish blood on the toilet paper. And I was like well sh*t I'm out... so I put a tampon in and went back to bed well I got up and didn't have anything on it. well a few hours later I went to pee again and I had the pinkish blood again. It's been doing it all day but it's not enough to put on a pad or tampon. Could I have ovulated later than what glow said? Or is it AF letting me know she's on her way. Also, I've been having pinching sensations instead of normal cramps and my nipples have been extremely sensitive and hurting which they have never hurt before my period before. I'm supposed to expect AF in one to two days.