I think your position is ok, actually. I was like you, I became concerned only after my children had had some vax.
They all had their DPT (before 5-in-1) but with the second and third it was delayed by a few months. Now, I wouldn't do it at all, but that's easy to say after the fact.
The others, I just delayed until one day I thought that's it, not going to happen. I didn't tell the surgery. I would be recommended on every visit, for whatever reason, and say ok I'll make an appointment, thank you very much, and just walk out past the receptionist without doing it. I didn't want to have the argument, which I always felt was rather pointless.
It's ok to delay, I think, rather than decide. I can imagine that you are thinking, oh my gosh, winter coming up, lots of bugs, couldn't forgive myself and so on. And to be honest if you are going to do it, every month that you delay is a benefit.