It is normal for this time of year. Cats are polyestrus, meaning the go into heat with the seasons and pretty much stay into heat until bred. Yes it is very stressful to her I would recomend getting her spayed as soon as possible, because you are putting her at risk for mammary cancer or pyometra (and infection in the uterus that is life threatening).
Thanks so much you guys! She is now about 3 yrs. old. Now this is the shocker: She has constantly been this way for almost two years since I got her. The worst part is that my vet said she can't be fixed until she is out of the heat cycle because it's too dangerous! She's only been out of heat for maybe 3 days at a time(at the most) and vets always require an appointment. I never know when she will stop again. I'm just hoping that this doesn't mean she has a hormonal problem or physical problem. Please respond.
Also, her name is Skittles and she is a medium hair tabby mix. She is sweet when she's in heat, but is really mean when she's not, haha! I adopted her and I will not abandon her as others have. She is part of a five-cat home and we love our fur babies very much.
They reason it is more expensive and a bit more risky is because the blood vessels to the uterus are much larger than a cat not in heat or a cat that has never been in heat. Definately find a vet who will do it while she is in heat, it will be a relief to you and her.
Vets can spay cats in heat, i really do think you should look for another vet, as you are doing your cats no favours by not spaying her. It may cost a bit more, but i think it will be worth it for both you and her.