I can offer some general insights that might help you understand why they blocked you.
Avoiding conflict: It's possible that your ex and his new girlfriend decided to block you to avoid any potential drama or conflicts. They might feel that keeping you out of their social media circles would be the best way to prevent any further emotional entanglements.
Privacy and boundaries: Blocking you might be a way for them to establish boundaries and maintain their privacy, especially given the sensitive situation of the pregnancy. They might want to keep their personal life private and shield themselves from external influences.
Moving on: Your ex might have reached out to you for various reasons, such as seeking closure, validation, or simply rekindling the connection. However, he may have realized that it was inappropriate or not helpful for his current relationship, and decided to cut off communication by blocking you.
Respect for his new relationship: It's possible that your ex's new girlfriend wasn't comfortable with him maintaining contact with an ex-partner, especially if there were unresolved feelings between the two of you. As a result, they both decided to block you to prioritize their current relationship.
Emotional reasons: Emotions can be complicated, and it's possible that your ex and his girlfriend decided to block you based on their own emotional processing of the situation. They might be trying to create emotional distance to move forward with their lives.
It's important to remember that social media interactions may not always reflect the full story or the true intentions of those involved. If you're feeling hurt or confused about the situation, it's best to focus on your own well-being and healing. If you believe there are unresolved issues that need closure, consider seeking support from friends, family, or a therapist to process your feelings in a healthy way.