Please helppp!!!!Hey ladies I have a question. Have you ever been on your cycle and something that…

Please helppp!!!!Hey ladies I have a question. Have you ever been on your cycle and something that looks like skin came out of you?? Because that's what happened to me when I started my cycle. three days into me being on my cycle Saturday morning I went to change my tampon and a piece of skin like thing was on it it was pink and it had dark blood at the end of it is that normal?? I wrote my OB and he says to consider taking a pregnancy test but I took a pregnancy test in July (blood work) it came back negative and I was told that I can restart my birth control again so that's what I did. I'm not understanding why is he telling me I should consider taking a pregnancy test if the blood work came back negative that I wasn't pregnant in July this shit is confusing me. Please tell me I'm not the only one that's ever went through this