Pos opk 3 days before af?

Hey all I don't know why but stacking up for next month I grabbed some more opk's at the store and tested today because I've heard it might be possible to ovulate twice in a cycle and my bbt chart was looking odd, well my opk did show an lh surge, there was a light pink line that is cleat seen. My question is what are the odds of this happening? If twins run in my family does this mean I could have ovulated twice even though I'm on a normal 28 day cycle? And what are the chances of this May be a sign of early pregnancy? I took a test yesterday but bfn, will take one tmr when it's 2 days before af but I don't want to get my hopes up for a bfp. I also had a big dip in my bbt 2 days ago and then after it slightly rose again. Thanks all in advance!