So sorry for your losses.
A lot of urine tests can pick up HCG before your period would be due so perhaps you could try testing early next time. Early response can be used up to 7 days before a period is due and MDS quick cards that you can buy at new world pick up hcg at 25 which is really low, above 5 is considered pregnant but most tests don't pick up until the level is 50.
Even with my m/c I still got a faint positive on the Friday and my period wasn't due until between sunday and tuesday (I have a 26-28 day cycle).
If you start charting then you could work out where in your cycle you ovulate and then test 10 days later, which would be before your period but late enough for an early test to pick up. I have never charted so can't really help with that but there are lots of ladies on here that do and could help you with it.
Like busymum I also had a really bad period the cylce after my m/c which involved heavier bleeding and worse clots but the cramps weren't quite as bad as the m/c. I was warned by my gp that that could happen as sometimes not everything comes away with m/c itself, and I knew for sure that time that I wasn't pg.
Edited by cuppatea