Thanks for the query to H.C.M. Forum.
Since you are a young female ,child bearing age and you are having irregular bleeding and amenorrhea
( as you mentioned that there was no bleeding for 7 months).
In my opinion the reason of these symptoms may be .
1 Poly Cystic Ovarian Disease
( PCOD) , diagnosis can be confirmed by ultrasound
of abdomen with emphasis over both kidneys. As you have taken depo provera , this is nothing to do with this menses irregularities , so need not to worry about that.
2 The next reason you mentioned in your query "endometrial cyst
" as diagnosis was already , so get in one more ultrasound of uterus and confirm about any fibroid in uterus and any progress in the size of endometrial cyst.
imbalance is the another so get in estrogen , androgen as well F SH/ L H ratio.
In my opinion consult a gynecologist and get his opinion (2nd ) for irregular bleeding.
Good luck. Dr. HET