2nd miscarriage in 2 months.??

So d miscarriage in 2 months and Drs say they don't know why. I have two healthy children almost 7 and almost 5.. I had mirena for 4 years and since taken out have had 2 unexplained :( any one have this happen and then have a normal pregnancy? Not really sure what to do next, except feel like something is wrong with me