This is exactly what has happened with me. I turned 25 weeks on Tuesday, and since the Sunday before, the movements have been a lot less intense (She was super active the week before, culminating in a full on rave on the Saturday). I ended up going in to see the Midwife on Monday and she used the doppler to show me baby's heartbeat is fine. I've got my 25 week appointment today, so will get them to check again, but my assumption is she's moved position in the last week. She was breech at my 20 week scan, and I felt all the kicks at the bottom of my abdomen. Now there's a light fluttery feeling there instead which I think might be hiccups, so I assume she's turned the right way up and I'm not as sensitive to kicks where her feet are now.
I'm 24 weeks 25 on Monday, the day I hit 24 weeks baby was the most active he's been, this week he's more active in the morning and then in the evening. I was so the hospital last week and they told me babies develop a pattern at 24 weeks, I see my midwife today so will eb speaking to her about movements. I'd get him checked, they would prefer you to be checked even if things are slightly different x