SAHM vs Daycare

Jessica • Married {05-11-13} Mommy to two beautiful little boys Kobie {9-2-13} & Kruz {4-7-16}
I just had our second son almost two weeks and I've been very fortunate to be a SAHM with our two in a half year old and I plan to be able to do the same with this little guy too. But my husband has been nagging me nonstop to put our two year old in daycare 2-3 days a week because he thinks he needs to be around other kids more. I am so frustrated because he is around other kids...he plays with our neighbors, he does gymnastics every week, and I have a lot of friends who have kids his age. Everyone tells me how great he can speak and hold a conversation. He's just VERY energetic and stubborn. He has a hard time following directions. I'm guessing that's why my husband thinks he needs daycare but my MIL planted that in his mind 😑 she's always telling me "I never got to stay home with my kids they were in daycare at 6 weeks old. They're going to get sick and that's just that." It's so frustrating. And also having a newborn in the house I don't want to expose him to all the germs my two year old will get bc I know he'll get sick a lot having not been in a daycare before and I know no one is going to care for him like I do. 
So my husband is leaving to go run some errands with our two year old and he says I'm going to swing by the daycare on the way home and get all the paperwork. I just don't even respond. I have half a mind to fill it all out and tell my husband he's going and just not take him. I'm his mom...if o felt he needed daycare I would do
It. I feel like my husband doesn't respect my decisions as a mother. 
I'm just looking for some input from the outside looking as if I'm overreacting or not?