My doctor did a ultrasound and said they saw subchronic bleedind is that a concern in a pregnancy?

Subchorionic bleed: This answer depends on many factors. Generally a small bleed is not a concern. It is more of a concern depending on if the mother is symptomatic, age of mother and stage of pregnancy. Small, asymptomatic subchorionic hematomas do not change the outcome.

Sometimes: Early in pregnancy it's not uncommon to see this on ultrasound. It usually resolves over time and your OB may follow you with ultrasound until then. If you don't have cramping or bleeding, it rarely affects the pregnancy. Tell your doc if you have any of these symptoms & good luck with your pregnancy.