I got pregnant after 2nd IVF and when they told us at 6wks we had a heartbeat I burst into tears, convinced that this was just a new way for mother nature to taunt us before taking it all away! The anxiety about losing him went at...ooh 30 weeks? And was quickly replaced by anxiety of prematurity, followed by anxiety of every other thing that you can read about on t'internet! So it's completely normal I'd say. But it will get incrementally better and better, as everyone else says.
As regards other people's pregnancies- would it help if you started relating these babies to your baby? EG- x's baby will be in the same school class as our baby...they could be mates...or get married.... I found that really helped me imagine my embryo as a real person. But I can understand if she thinks that this is tempting fate.
I also always found it encouraging when my uber- optimistic husband said things like 'it's okay...it just means our baby will be the youngest and everyone will pet him/ her as the baby of the family' in the face of a failed round of fertility treatment!
More contraversially, perhaps, I also found it useful when he pointed out to me that other people's pregnancies have zero bearing on your own ability to conceive- 'there are not a finite number of babies in the world...x hasn't taken one away from you'. It seemed a bit harsh at the time, but it actually really changed my thinking and made me feel much more positive when dealing with other's news.
The other thing we did was lavish presents on people when they had kids, hoping that some kind of 'what you reap, you sow' principle might kick in and give us good IVF karma. Once we decided to have this attitudinal change ( other people's pregnancies- brilliant! fabulous! fantastic! tell us more!) we did find it helped. At first it was a bit forced but it did make it more bearable, if only because other people weren't pussing footing around us. All pregnancy = good. I know it sounds a bit odd but it worked for us.
Err, hope that helps. So much good luck!