Do not panic if your gums appear swollen or when brushing you notice blood on your gum lines, your toothbrush or in the sink. This is a very normal symptom that can happen in pregnancy due to the increase of pregnancy hormones making the gums inflamed. It is called Gingivitis. It can happen to anyone at any time but in pregnancy it becomes more common.
If the gums become inflamed they become more prone to bacteria found in plaque that lays down on the edges of the gums. This will lead to them feeling swollen and sore and then when brushing can bleed.
It should settle down post pregnancy but during Pregnancy it is hard to make Gingivitis go away but you help prevent it turning into Periodontitis with good Oral Hygiene. Periodontitis can increase risk of low birth weight, premature labor and possibly preeclampsia.