Late Period

I'm 15 days 'late' for my period according to the app my doctor had me on Provera to bring back my period. Which worked for two months and now nothing! I took a pregnancy test on the 21st May, so I was pretty much a full week late and it came back negative (plus a billion negative tests prior to that too), so not pregnant. Is there anything I should be asking my doctor for to help get my period to come back?? Anything that has helped anyone else with irregular/absent periods??

Edit: my doctor has done 3 lots of blood tests over the past 4 months and they have returned normal too 😭