Help? Is this normal or not

Basically sounds rank but getting worried now, I am 16 been having periods for like 3 years now... I am now on the injection and had 2 periods since being on it, they are normal ish last a bit longer than they used but that doesn't bother me. On like the 5th day this massive like bloody, hard, lump come out... It's like the size of a walnut no even joking.. I have never had this before but had them the last 2 periods, little worrying... I had an abortion in October could it maybe something to do with that? It's horrible