Honestly? Yes I would judge, especially with relatively small gaps between the children.
I think you've been irresponsible moving him in so soon.
The first year to 18 months you're in the rose tinted, honeymoon phase of a relationship, I wouldn't advise anyone moving in together earlier than 2 years together and especially when there are children already involved.
You need to stop prioritising your love life over your kids.
And thinking you need to have a baby with every "serious" partner.
Quite honestly with kids in the mix at a year in they should just be getting to know him and you should be keeping an eye out for what his faults are and if they're deal breakers or not and he should be doing the same with you.
Are you very young? You sound young.
Seriously all way too much too soon. Double up on contraception and be fastidious if you're on the pill.
The last thing needed here right now is another child!
Also if you think marriage is "just a piece of paper" you're incredibly naive and need to educate yourself. Marriage is a legal contact that covers rights and responsibilities on the parties in it.
As for you thinking your home is secure because landlady is a friend - again incredibly naive. You have a rental contract I hope? Even if you do that is not guaranteed secure housing.
Sounds to me like you've a lot of growing up and learning to do.