Not sure if I should see a doctor?

So I recently started taking a combination birth control pill and I waited 7 days as recommended before having unprotected sex with my boyfriend. We’ve continued to have sex without condoms since then, and it’s been about a month since I started the pill. I didn’t get my period during the first sugar pill week, which I was told was normal so I didn’t think that I was pregnant. However, about a week after I started getting SEVERE cramps and medium bleeding, and then comes the gross part. I passed a giant blood clot but it had some white tissue mixed in with the blood? Almost like it was half blood clot half skin... Is it possible that this was a miscarriage or should I be concerned about my health? Thanks ahead to anyone who replies!!