Nipple piercings-bump?

Destiny

So I got my nipples pierced about 6 weeks ago and noticed a bump by one side of the piercing. Then I noticed another, bigger one in the other one too, it literally popped up in like 20 minutes and was red like it was filled with blood. Later I guess it ‘popped’ because there was blood at the piercing site and it look drained. I haven’t changed the rings either. Anyone have this Issue or know what it is? I’m scared my body is going to reject them like it did my bellybutton piercing (x3)