I know this post is old but the pattern my daughter had at 4 months was to nap every 1.5-2 hrs, just like one of the other posts said. So it wasn't a "schedule" at al as it depended on what time she woke up just like another post said. But once she was up, you could watch her and see that she was sleepy within 1.5 - 2 hrs, and then that pattern would repeat itself. her naps would vary in length but you could count on a bunch of them throughout the day.
I agree with the suggestion to keep a journal (document her naps, feeding, how much and what she ate etc) - we did and it was helpful to see her patterns, also helped me know about her days when I went back to work I didn't want to miss anything.
Her last nap would be a "cat nap" in the late evening to rest of for bedtime : ) . Then we'd feed her as much as possible before putting her down, and I would dreamfeed before going to bed (feed without waking) so that I could get as much sleep as possible.
Eventually, she morphed into three solid naps until she was over a year old, then to two nape sometime around a year and a half.
congrats and good luck