If my gums bled a lot while i brushed my teeth, could that be a sign of pregnancy?

Not really: Bleeding gums are signs of gum infection, hormonal changes such in pregnancy can affect the physiology of the gingival tissues but alone will not cause bleeding, a pregnanacy test is more accurate then having to wait for your gums to bleed, if you are pregnant and have gum disease your gums will tend to bleed more. Please visit your dentist to treat your gum disease.

Bleeding gums: Yes it may, as hormone fluctuations occur, but it can indicate many other issues too- anemia, gingivitis, or just brushing with too stiff a toothbrush, for example. I recommend contacting your primary doctor for an exam.

Yes, it may: Bleeding gum is a sign of pregnancy gingivitis, occurinng during pregnancy due to the rise in estrogen and ultimately break down into estradiol, a potent bacterial growth factor.