Is there time to think about it? I had my first at 28 and did not feel ready for a second until my first was 4+ for a ton of reasons, including having a VERY difficult child (later diagnosed ADHD).
I then dealt with unexplained secondary infertility for a while, which put me on the other end of things - wondering how I would feel if I just wasn't able to have a second.
I'm an only and I had a good life. I always saw myself with more than one, but it was not because I had problems with being an only.
We did eventually have a happy surprise second child. They are 8.5 years apart. My second child is much easier than the first. At least so far
Unless you are feeling pressure to have a second, give yourself some time to think about it.