Ok, I wanted hard data.
Most babies are born between July and November, so most babies are conceived during the colder months (which makes sense -- people stay inside more, and probably have sex more).
https://www.smithsonianmag.com/science-nature/more-babies-are-conceived-during-winter-fall-180971112/
And PP is right that August is the most popular birth month. This article points out that a late August birthday usually means conception around Christmas/Hannukah/New Years.
https://www.unitypoint.org/livewell/article.aspx?id=ad80d6cc-6a53-49f3-b496-8c0f48b47936
And a late July or early August birthdate means Thanksgiving. So not only are people inside, these are times when they tend to be celebrating, maybe drinking more.
Anyway, your observation is just anecdotal OP. Turns out people are more likely to be having a baby in July than making one.