Congratulations
My LO is my rainbow baby after a miscarriage with no period in between. When going to the OB they always stated they wanted the last period date and not the miscarriage as it’s not actually a “period” This did cause confusion until they were able to get a dating ultrasound, however I would always mention my last period date but I had a miscarriage in between with a back to back pregnancy. Realistically the cycle does continue from when you started bleeding for the MC but this is based off my experience
The first day of bleeding from a miscarriage marks the start of a new menstrual cycle, and ovulation can occur within the same cycle. ^ This was a summery of most of the answers I could find when I looked it up.