Pregnant lovebird?

Question
Three weeks ago someone gave me a pair of lovebirds, one male and one female, plus an egg.  (I have never owned birds before).  They both have been playful, active, and curious.  And they mate quite a bit.  The female one was friendly right off the bat, and sometimes the male would get jealous and start pecking her.  After two weeks the male seemed to let loose and became friendly as well.  Recently the female one does not seem like her usual self, she seems tired all the time and sometimes just stays in the bottom of the cage, or in the nest box.  She sleeps a lot and does not move around much. She still eats and drinks many times a day. I have seen the male feeding her while she was in the nest box, so I figured she was just trying to keep the egg warm.  But then yesterday I saw her breathing pretty heavy, which really worried me.  Today she seems better, she stayed by the food container all day and ate whenever she felt like it.  I was wondering if this has anything to do with the birds mating, and if that's a sign that she's laying more eggs (the other day I found another egg), or if it's a sign of something serious.  

Answer
Hi, Janine.  Thanks for posting!

Any time a bird sits on the bottom of it's cage or has difficulty breathing, this is a serious situation.  Also, your lovebird could be egg bound...signs are similar.  I recommend you get this lovebird to an avian vet immediately.  Not a cat/dog vet, but a certified avian vet (exotic animal vet).  Do not hesitate or you could lose your bird.

Chrys