I had a fibroid and was detected on my first scan at 7 weeks. it grew to more than 10cm but no bleeding. I felt sharp pain for 2 times during the pregnancy and took painkillers and given HL to rest for a week each. until now I'm not too sure if it's the fibroid or some muscle strain. size reduced by more than half after giving birth and I removed it via keyhole surgery 6 mths later. baby was not affected but I was recommended csect due to the position of the fibroid
I also had a fibroid during pregnancy and it was only detected during the detailed scan. But i had no bleeding or spotting at all. The fibroid went away after my pregnancy.