off the mini pill to conceive

Kayleigh
Hiya, I came off the mini pill a week before Christmas to start to try for another baby. It took 12 weeks before af showed up. We had sex the weekend I finished af and 3 time through my overlation days. Iv had really sore and tender boobs and nipple since then, this week it's only 1 boob that seems to be tender. Iv also had cramps and feeling really tired all the time, even if I have 9 hours a night. 
I'm slightly confused if this is period retaliated or early signs?? Help 
Will be taking a test next week as af is due to show on Monday according to this app. But then again I'm not sure as I haven't had a regular cycle. X