Chemical pregnancy 4 weeks...

Took tons of pregnancy tests. All lightly positive, never progressed. I knew something was up. Sure enough, today, I miscarried. Went in for HCG labs (was down to a 3) & a RhoGAM shot. I had a chemical pregnancy back in 2014 — fell pregnant with my daughter in 2015 (successful pregnancy). I tracked this cycle that I fell pregnant on with opk & we tried Preseed for the first time, & fell pregnant... so sad for our loss but blessed it happened sooner vs. later. I just am left wondering what happened... is my body messed up? Why? I pray we get pregnant soon! Any advice for future TTC? Thank you!