new mother - may be in trouble?

I don't know what information might be relevant so I am going to tell you everything I know. My 1.1 year old female cat just gave birth to 5 kittens on Monday. One died that same day. The rest seem fine and strong. Well a few days ago I was petting her and I felt like a bulge in her and thought it might be normal and she didn't seem like she was in pain. Tonight I was petting her again and her bottom two nipples, the ones closest to her birth canal, are inflamed and have like a bulge underneath them. She still has a good appetite, is mobile and is nursing and does not seem to be in any pain at all when I pet her there. However her ears are very warm and I can't tell if this process is normal or if I should take her to a vet right away.

[Soror]

I'd get her to a vet.  The bulge might be her milk glands, but she might have another kitten she hasn't birthed yet.  No harm in getting her checked out.