I would totally request testing!
Your story sound a lot like mine. I carried 3 healthy baby boys, with no issues at all. Even had natural home births with all three, so really model pregnancies. Then about a year and a half ago got preg and lost at 7 weeks. Had a chemical the next cycle, then the next cycle another bfp, only we lost that one at 11 weeks. After that, my midwife did a round of testing for genetic issues, possible deficiencies, etc. I wish I could say she found something that definitively pointed to why, but all my tests came back fine. She did say due to MTHFR I should probably be takgin baby aspirin when TTC again, but she also said that was unlikely to have been the cause of my losses. Maybe my age was a factor (38), maybe something else. Frustrating not to have answers, I know!
The good news? After waiting almost a year to TTC again after the last loss, I'm now due with a healthy baby GIRl in October. Fingers crossed she stays sticky, but so far so good.
Big hugs to you! It's so hard and not knowing why really sucks. I hope the tests can provide some answers.