What’s going on?!

Hi all,

A brief history... My cycles seem to be all over the place though I am not charting. Basically I had my last depo injection in March after being off it for 9 months but had been on it for 6 consecutive months prior. Depo was due to be done again in June but I decided against this and AF returned in July for a week and was 'normal' for me. Came again when I would usually expect it in August but then a week after finishing I got it again... Finished a week later and today after a week I have it again! Hope this makes sense... So dates are...

19/7/12-24/7/12 - AF
5/8/12-10/8/12 - AF
18/8/12-24/8/12 - AF
30/8/12 AF arrived.

Dr thinks it is a result of depo but I'm not sure... After coming off Depo in July 2011 my AF came back in Dec 2011 and came every month and was my 'normal' until I went on Depo in March. At end of March I had a 'scare' and Dr thought I was having a miscarriage because I passed a clot but HCG was low/negative.

Just wondering if I should go back to the Drs. I went last week for some heart related stuff but mentioned it in case it was the medication I was on but Dr didn't think so as Af had started before I went on the meds.