Is it petty to breakup at this time?

I think I've come to the conclusion to break up with my boyfriend. I had told him he had a few months ago that if he still was unsure about marriage by this Dec that we should break up. I'm fairly certain he has not started looking for rings. In addition, our timeline for children are not even close to the same. I want to start trying in like 4 years. He said he's not opposed to kids but didn't seem excited about my timeline and didn't offer his own. He said he didn't want to talk more about it. Is it wrong of me to end it sooner than Dec even though I said he has till then? We have a trip together next month that's paid for so maybe after that? We've been together 5 years now.
Is it petty to breakup at this time?
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