Late again

So my cycle has been pretty regular for a while, roughly 3-4weeks between periods. Well since around May, they have been starting to space out more and more. I went 5 weeks one month and in pushing 7 weeks right now, and I still haven't started yet. My hubby and I do use condoms every time we have sex, so I know im.not pregnant. But another thing, back in July and August, after I was done with my period, around day 10 of my cycle, both months, I would spot for about 3 days. During this in July, I actually passed a blood clot. I'm not sure what's going on... Any ideas?? **Also, I'm 22 and not on any form of B.C.**