2 yr old Beagle in heat, miserable

Our 2 yr old beagle has reached her second heat. We plan on breeding her to a relatives male beagle just this once. After that, we plan on having her spayed.
   
In the mean time, her first heat was a piece of cake. This time around, she is really swollen, hasn't bled yet,I'm sure tha's coming in the next few days, but is almost depressed. She is whining terribly and agitated. She is lying around. Even our kids have noticed she seems "sad". I realize she basically has her period, so is it Ok to give her ibuprofin, or half an asprin? The poor dog is miserable. She can't seem to get comfortable. Any advice on helping ease her pain?
   
Ps. She's not pregnant yet, this we know for sure, she hasn't been around any males, and is an only pet.
   
Thanks!!