DD is 4 and a half weeks old, and generally she's great. Feeding well, sleeping gradually longer and longer. A perfect baby (well, nearly - I'm allowed to be biased )

It's been a rough afternoon. She's been unsettled or just downright crying all afternoon, for about 9 hours now. We don't know what the problem is (maybe more than one problem?).

The one thing we've noticed is that she's needing lots and lots of nappy changes, because she's doing lots of little poos and little wees and she gets upset each time. So we've changed her nappy maybe 12 times in the last 9 hours. Actually it feels like more, but I lost count a few hours ago...

I fed her (bf) at midday, 3, 5.45, 8.15. This seems a little too frequent to me - she's been feeding 4-hourly in recent days, very regular. I am not sure whether she is partly, or sometimes, crying because she's hungry, or whether she's crying because something is wrong that the more-frequent feeds are only exacerbating. So I don't know whether to feed her more or to try to wait it out for at least 3 or 4 hours since the last feed.

The last 3 nights at this time she's been sleeping for a 5 hour stretch. Tonight, 20 minutes after a feed, she's crying again It's really starting to stress me and DH out, because we don't know how to fix whatever the problem is.

Any idea what might be doing on? Is this a normal variation that we simply hadn't encountered before?