I noticed my dog limping and could not tell why, then i noticed she was biting at a bump between her belly and her leg,it looks like an extra nipple,is there anything i can do so i dont have to take her into the vet any alternative medicine?
It sounds like an allergic reaction - possibly from an insect bite or even contact with a plant. You can give benadryl (diphenhydramine) at the rate of 1 mg per pound of your dog's body weight. Make certain it is plain benadryl only, with no added decongestant.
If the swelling is worse in 24 hours, you can't avoid a trip to the vet. Keep an eye out for any further allergy-related problems like labored breathing. That would require emergency care.