How do I know that I am truly a submissive?

Okay, so my girlfriend and I just recently broke off our relationship, we were together for 3 years and we were into M/s and light BD/SM. I was the submissive and I was happy, that is, until she became more and more submissive and I felt I had to step into the dominant role, so, my question is, if I had the feeling my partner is preforming inadequately and I step up into their role, does that make me a dom? Or am I just an impatient submissive?