bio baby and step kids

I honestly feel awful, since i have gotten pregnant (9weeks today!) i have lost all connection with my step children... I’m not bonding with them like i use to... they are started treating me different... actively telling me they want their mom and not me... it hurt my feelings and i like completely detached.... they are only 3 so they didn’t mean to but i can’t help but feel like I’m not going to treat them the same as my baby... i love them but the love for my baby is different....and it’s causing me to be pretty sad because they didn’t ask to be here or do anything ... idk what to do... help