I have 2 sore, red/purple lumps on my left lower shin and ankle. At first I thought they were just bruises, but being that they've remained the same for 3 weeks, I'm thinking it is Erythema Nodosom.  I've read it can occur in pregnancy or when taking birth control.  I had ED when I was 14 (I'm now 31), following a bout with step throat and now it's back with my 4th pregnancy...