TTC after a loss (complications!!)

I had a miscarriage at 11 weeks (blighted ovum).

I took the pill to pass it- didn't fully work. Had a D&C-; didn't fully work.

Took the pill again- didn't work at all.

Had another D&C-; finally got it all.

So all of that happened in a month & a half (in March & April 2017).

I have 3 kids, and I'm 21. So I've been very fertile before all this. I've had 3 periods since then, 2 weeks apart. Now, I'm a week late (past a month) with 2 negative tests. We're not TTC YET, but we don't mind if it happens earlier. I'm just scared that when we do try, I won't be able to get pregnant because of everything my body has gone through this past year. (I'm not on birth control, and we do not use condoms. He pulls out most of the time, & this has always worked, but sometimes he's late about it or has "accidents" which I think are on purpose😉)

Is there a cheap/free (with insurance covered) way to check my fertility??

Has anyone else experienced this & gotten pregnant? Our goal was to start TTC within 2 years.

If my period is beyond late & my tests are negative, could I possibly not be ovulating at all? Or too early?

*We didn't TTC our other 3 children, they were just from not pulling out. I liked how easy it was for us. Now, I'm scared it won't be.