Lost my bb 😓

I went for my routine check up yesterday happily as I am supposed to be week 8+6. However I was told that there is no more heartbeat. I am in so much shock as the heartbeat was very strong just a week back. Gynae said this may be due to genetics issue but I can’t help to think if it’s because of us having sex once a few days ago. We were very careful to be gentle and slow. My pregnancy is a high risk one and I have been taking progesterone daily. We had sex once around 7 weeks but bb was healthy and heartbeat was strong after that so we didn’t think it would be a problem. Can someone please tell me if it’s because of us that we lost our baby ??? 😓😓