3 week old won't sleep today!!

Please help! My daughter was born on 6/2
She sleeps for 1.5-3 hour stints all Day and night with a couple 1-2 hour awake periods in the evening and morning. Today she hasn't slept for more than 15 mins, she wakes up, breastfeeds, falls asleep and then wakes up again no more than 30 mins later 
I know she's tired, she's doing this thing where she's rooting with her eyes closed, burying her head in my chest, grunting.. she's so tired, but I just don't know what to do, she seems so unsettled today.