No I don't think it's the drugs as I only had 5 injections which is not enough to make a difference - also that was in August and I did have my August period which was on 25th August, normally, after those needles.
I had no drugs since because of the side effects and was waiting for 'day 1' before visiting the clinic again, except day 1 never happened.
And actually after I backed off from Andy, I am not stressed in the least. I'm also never more than a week late normally, never, since I started my period at age 12.