Our first female beagle, Molly, bled for close to 40 days. It seemed like she was in heat for about 2 months, from symptoms start to symptoms finish. We took her to the vet at about day 32 of her bleeding, and our vet said not to worry, especially as it was her first heat cycle. It went away, and all was fine. He said that her next heat cycle should be shorter, more normal. Sadly we never found out. Our second female, Bella, is a year and almost 5 months old. She hasn't gone into heat yet. We talk to our vet about it every time we are in to see him, but he also says it is no huge deal, she is perfectly healthy as she is.
Good luck!