Yes it is definitely possible.
When a dog is in heat its symptoms may differ based on its breed size and age. Some female French bulldogs tend to bleed heavily when they are in the proestrus period while others may have minimal bleeding. The term "silent heat" refers to the fact that some bitches may not even bleed at all. Although they ovulate they do not show any signs. Keep in mind that a woman can still conceive even if she does not show these signs. If you intend to breed your Frenchie it is not a good idea to just rely on the presence of bloody discharge. As well as aggressiveness a swollen vulva etc. you should observe any other symptoms.