Bb heartbeat

Ok m 39 years old, high risk mother to be. I’m currently about 5 weeks pregnant. Abdominal scan can see the sac but can’t see heartbeat. These few days I have brown discharge on n off. Am currently on Utrogestan. Is it really too early to see heartbeat. I’m v worried. I waited For this miracle bb for 10 years since my first kid in 2011. 🙏