Hello, Thank you for your query. I understand your concerns. Is the bubble that you felt in the vagina or near the anus (i.e. the back passage opening from where the stool comes out)? If it is inside the vagina, you can see your gynaecologist. My diagnosis is that you may be having piles/haemorrhoids. Haemorrhoids/Piles are very common in pregnancy and that is the commonest cause pf bleeding from the back passage. Haemorrhoids/piles are small lumps that are present into the lower part of the anal canal.They are filled with blood vessels. Due to pressure from your enlarging womb (due to pregnancy), these lumps can pop out of the anal canal and thus you can sometimes feel them outside. As these lumps are very soft, when you have constipation and straining to push the stool out, or if the stool is hard, it can cut the thin covering of these piles and cause bleeding. Sometimes, these lumps can be painful too when they are inflamed. You can use creams like Anovate or Proctosedyl twice a day after opening your bowels near the anal region which will help. Cervical causes will not cause bleeding from your back passage. I hope this answer has helped you. Regards Dr Sunita Sayammagaru