First, therapist #1 won't know just because of the deductible, which can be reached with lots of other non-mental health related visits and tests.

Second, seeing #3 might make you feel even better about #1.

Third, seeing #3 might create confusion about #1 if you really like #3...but just based on my own experience, I really doubt this. It's hard to find one, let alone two, good therapy matches in such short order. It is possible though, and I think that's what worrying you.

Fourth, if seeing #3 creates confusion, it might help you further clarify what you are looking for in therapy and a therapist. You can deal with that, though, if and when it happens.

If you don't see #3, it sounds like you will always be wondering. Would that wondering eat away at you? Or can you let it dissolve, knowing you like the one you're seeing now?