Help. What just happened.

Brittany • Our baby boy born July 2016 💙 Our angel baby was taken Oct 2018 💔 Our Rainbow baby girl born Aug 2019 🌈 Currently TTC 2022
Hubby and I just had sex. We TTC last week. . As soon as it was over bright red blood gushed from my vagina. Not a large amount and it quit quickly. Is this a sign of pregnancy. Or what causes this. No pain or other unusual symptoms involved.