Two miscarriages - now what?

Jenny • Late 20's. TTC #1 Recovering from 2nd miscarriage at 6-7 weeks.
Just found out today that I will have my second miscarriage. The first one was at 5 1/2 weeks. This one is closer to 7 weeks after having success with our first IUI. There were two sacs but only one embryo. 
The embryo is still in there (stopped growing at 6 weeks 1 day) but with a fading heartbeat. I have to wait for it to stop before we do anything. Still debating natural vs. meds vs D&C but leaning towards natural (w meds if it doesn't happen quick enough).
Pretty heartbreaking. My husband and I are 29 and 30 and healthy - TTC our first. All of my tests came normal (Day 3, HSG, genetic testing etc). My husband just has mild progression issue but otherwise fit as a fiddle.
I'm wondering now that I've had two miscarriages in a row (a year apart) if we should move on to IVF (w genetic testing) or give IUI another shot. The doctor seems to be proposing both as options.
Currently just sad and angry that I'm the 2% that has two miscarriages in a row. Worried there's a bigger issue here that I don't know about. Nervous to try IUI again. 
Jen