10wk old sleeping a LOT and eating less - worried. Any suggestions?

Chan4dra04

My DD is 10wks old currently.  She had her shots at 8w5d, so I'm not sure this is related to that event.  Usually, she feeds every 2 hours exactly from both sides (EBF).  However, last week til now has been a different story.  She's barely up an hour after eating, and isn't eating long on one side before she falls asleep.  Like, dead to the world sleep.  I'm worried for a couple of reasons:

1 - the obvious: is something wrong with her?  Sick?  Her temperament isn't any different, just the amount she's awake and eating. 

2 - EBF - since she's sleeping so much, she's missing feeds and not eating off both sides, let alone finishing one side.  Will this start to effect my supply? 

I'm concerned and really worried about her sleeping so much and that my supply will drop to accomodate her decreased needs, but won't be able to keep up if she somehow bounces back to eating off both sides every 2 hours.  Any thoughts, suggestions, experience would be so helpful!!!!!! 

TIA, ladies!!!!!!!!!!!!