Opk confusion!!!

Hi, new to this....ttc #2 have a 5 year old daughter.

Came off pill on 9th October. Had a bleed 26th- 30th Oct. +opk on 6th and 7th but then again yesterday and today!! (Cd15/16) but a -hpt.

Got sore boobs...cramps...fatigue.

So confused! Any ideas?