Warm salt water. Is not likely to help much or at all. Chronic gum bleeding is often related to gingivitis and periodontal disease. Please seek an exam from your dentist or a periodontal specialist for this bleeding for a proper diagnosis. Good luck!
Won't cure anything. Bleeding gums are a sign of some problem, most likely some stage of gum disease such as gingivitis or periodontitis, although there are both other dental and medical causes. Salt water rinses won't cure anything. See your dentist to find out exactly why your gums are bleeding and what treatment is warranted.
See dentist. You need to brush and floss at home to prevent bleeding. But if your gums are now bleeding and it has been awhile since you saw your dentist, you need to have a dental examinatino and your teeth cleaned. A healthy mouth is important during pregnancy.