17 weeks pregnant, been bleeding since week 14, no pain?

When I was 14 weeks I started to bleed alot of very watery light pinkish blood for just about 2-3 days. (The very heavy bleeding only lasted a few hours) I had a cyst on my umbilical cord and umed the reason for my bleeding was because the cyst burst. Now ever since that day I have been bleeding pretty much every morning. (It has recently cut down to about every other day) It's now only a little bit of dark blood that sometimes comes out during the night and sometimes first thing in the morning, the second I wake up. I am now 17 weeks pregnant and so far only felt a slight amount of pain at week 14 when this first started. I think it might have been psychological because I had convinced myself I was going to miscarry and I was very stressed. Well I've had an ultrasound and a sonogram a week ago and I was told everything was fine, but I don''t know I read online that bleeding with no pain can mean placenta previa which is supposedly very serious.