How to keep "baby fever" at bay?

I'm a nanny, and I watch 3 children at work. Twin 7 month old boys, and a 2.5 year old girl. I've been with them for 6 months now. I love working with them so much! I've been a nanny for 6 years now with different families, and (although I love all kids I've nannied for) I think I'm the happiest I've ever been with this job. Their parents and I have the same parenting styles, and we're always on the same page about everything. Some other parents were very different from me, or had parenting styles I didn't really like or agreed with, and it made the job more tiring for me. (Obviously I'm going to do exactly what the parents wish since it's their child, but it definitely makes the job less enjoyable and more stressful when you don't entirely agree)

The kids are great for the most part, and if it's a tough day or they're acting up, I usually see it as a necessary challenge, and I enjoy having my skills as a nanny challenged because I come out learning from it. I never used to think this way with some of the other children. It was simply stressful if they were difficult.

Overall, this job is much better for my mental health and every day I go home feeling like it was a good day, even if it was a little stressful. I think it's beginning to have an effect on my baby fever.

My boyfriend and I always talk about children, when we want them, when we're going to get married, etc... We both agreed we're going to get married in 2021, but we haven't officially gotten engaged yet because he's planning something special for the proposal. I know it's coming soon, and he's constantly hinting at it.

We own our own home, and have lived together for over a year now. Financially, we're stable and we each have great jobs. We agreed that if we ended up having a baby right now we would be just fine, however we both want to be married first. We also have a few overseas vacations planned, and we want to make sure that we have enough money afterwards to start TTC. We're thinking of TTC about a year or 2 from now. Obviously I want to wait to have kids, since we have so much we want to do beforehand, but I can't help my extreme baby fever. Does anyone have any tips to help me keep my sanity for another year?