my wife is about 6 weeks pregnant and had similar experiences. she has also had a miscarriage before and worries at the slightest sign of pain or blood.

we went to the melbourne royal women's emergency room to check everything was fine, and saw a really great doctor who gave us some great reassurance.
he said there was nothing anybody could do, 1 in 5 pregnancies ended in miscarriage (not a reassuring statistic in itself), but that you should really only be worried about great amounts of pain or blood.

he said to think of it not as bleeding from your vagina, but bleeding from, say, your hand. meaning, if you cut your finger and lost a bit of blood, you would not go to the hospital. if however you lost a lot of blood from your finger, you would get worried and go to the hospital.

sorry to be a bloke and unable to speak from first-hand experience, but i hope this advice my wife got helps you worry less. think of the AMOUNT of blood you're losing, not where it's coming from.