Help me please.. I’m confused

Okay so my periods are irregular I’ve been taking medroxyprogesterone to get them back on track .. last month (June) I had 2 periods the first one was 9-13th and this app said I ovulated 14-18th then I stared another cycle from the 27th-2nd (of July)) and the app says I ovulated the 9th through the 15 I had sex on 3 or 4 of those days .. when should I test? I’ve been getting negatives but ppl are telling me I’m testing to early according to this app my period is in 3 days .. which I’m not sure if that is really when it’s supposed to come .. also I’ve been cramping for a couple of days like it’s going to come but af never does (SO FAR)