Our 12 year old Golden Retreiver has a very swollen vulva. Is this normal?

Her whole backside is looking ready to pop. We started noticing it was swollen a couple of weeks ago and it seems to just be bigger! Tonight we noticed some bleeding like she is in heat but she hasn't been in heat in a few years. Do I need to take her to a vet or Is it normal for an older dog to go into heat after a few years (if that is what is going on)?