My bank did a credit rating and pre-approval letter for free. Any issues are listed out with a bottom line credit rating from 000-999 with higher being better. I rated in the low 800's without any credit issues at all which the loan consultant said was real good (commi$$ion).
Save up for a bigger down payment and it's easier to get the mortgage.
If you want a free report you can apply for a credit card, get declined and then state that as a reason for a free one. It use to be that TRW (now Experian) use to give one free one out per year. I think residents of the state of California still can get one for free.
If you're a vet look at a VA loan as they're the best thing going for those vets with credit problems. The rates and fees are not too bad at all and compared with the best bank rates.
I qualified for a Cal-Vet 80/20 program which requires active duty military, 20% down, no PMI, 1% loan fee and results in a 6.0% APR.
It may pay you to give up a point or two to get into a home now and re-finance (if rates hold) after a few years of good payment history.