They don't bring pollen in in large amounts all the time. They work as the hive needs it. Besides there are times when pollen will not be as available as at other times. Here Dandelion, Maple bloom are the first pollen times.
Clover

we should be getting clover up here in a few more weeks.
If God blesses it, we should be ready to get some honey this year.
I have been told that if the hive is very busy (coming and going) without a lot of delay to go in or out (unlike you see a lot of times where they seem to play around a bit before going in) they probably are on a nectar flow. Also bearding in the evenings with a lot of fanning at the entrance. Of course opening the hive is my method to check
