Cat spraying B/C Im pregnant

Please let me preface by saying Im more intriuged by this behavior than anything else. This is NOT a post about me wanting to drop my cat off at some shelter or having him euthanized b/c he is spraying!! 

Chase, (The love of my life) is a one owner cat. He was a feral and only attached himself to me. I have a colony of Ferals I take care of that live primarily in my backyard where their cathouse is. He normally loves them! He would chrip at them through the window and try and play with them through the sliding door. He would alert me if one needed feeding! Ever since I've been pregnant he is spraying the backdoor and every window he can get in. Its more the tom cat (who's eluded the trap for 1 1/2yrs!) and a random female house cat he really dislikes now! He is neutered so the smell is not strong and windows are easy to clean. I AM NOT MAD AT HIM! I realize he feels territorial b/c I feed cats so close but like I said, Im intrigued b/c he's only been this way since I've been pregnant. In a way I feel like he's trying to protect me. 

Has anyone else experienced this? 

He absolutely has a sixth sense! When each of my 2 older cats died from cancer he stayed with both of them until the end. He's amazing! Last year when It snowed he would cry at the window where I feed the cats. I think it was b/c I rescued him from a snow storm. I honestly think he is trying to protect me! He climbs on my belly, sniffs it then gives me kisses. Its the most amazing thing I've ever seen. My other 3 have gotten more lovable but Im on bedrest so Im also spending alot more time with them. He's just such a sweet cat, I was surprised at the sudden growling and spraying. 

Thats him in my siggy, he has a perfect heart on his forehead! So cute!