TMI + Image. Possible Miscarriage?

My period was 3 weeks late but I was so busy with other things I didn’t realise until I got what I thought was my period 4 days ago. It hurt so bad & was so so heavy (as in bleeding through layers of clothes a day, taking tramadol to ease the pain & feeling huge clots fall into the toilet). Around 4.30am this morning I woke up to find I’d bled through everything so I stood up & blood was pouring out of me. I went to the toilet to clean up & literally heard a clot fall out. I covered it because I didn’t want to wake anyone up screaming, sat back down & pushed (I couldn’t help it) & this fell out of me. Could this be a miscarriage? I don’t want to go to hospital unless 10000% necessary because I have a 7 month old son to worry about. It looked kind of.. veiny I guess is the word?