Low sex drive, help!

I am 8+ weeks pregnant with my second and my son just turned 7 months. I have 0 sex drive... I want to be close to my husband and please him. He is an amazing husband and father. He would never push me to have sex or complain if it's been too long. I thought maybe he was giving me too much space and asked him to initiate or try to seduce me... but still my desire is not there. I feel terrible and want to enjoy sex with my husband. Advice please!