daintree - I know how scary this is you poor thing. I have been bleeding (heavily at times) throughout my whole pregnancy. Sometimes it is painful and it is always bright red. It freaks me out every time it happens, but I am almost 28 weeks and everything is fine with bub. I seem to have a heavy bleed every couple of weeks and spot constantly in between, the OB thinks it is coming from the edge of the placenta.
I felt I had to share this because every time I look for information about bleeding later in pregnancy I barely find anyone else who has been through this, so I wanted to give you some reassurance. Definitely ask your OB, but sometimes they can't see the answer on the scans etc which is really frustrating. Have they checked the position of your placenta?
Hang in there, the chances of something going wrong now are very very low and quite a few people have spotting even in second trimester.
Good luck,
Lou.