Had egg retrieval yesterday...

I'm 40 years old and going through IVF for the first time. My baseline ultrasound showed 15 follicles...so I was feeling pretty positive, that's the highest follicle count I've had so far. Fast forward through a week of stimulation injections and my last ultrasound (on Sunday) showed 7 follicles. Had egg retrieval yesterday (Tues) and they only got 4 eggs. Waiting for a phone call today to be told how many of the 4 eggs fertilized. I feel so let down and worried. So many people have been telling me that they have a feeling I'd be getting pregnant soon... Some of those people don't even know I'm trying or going through IVF. My fertility nurses always compliment my test results telling me how "great" everything looks... They always make me feel so positive. I was feeling so good and so happy with all the uplifting test results & comments.... Then to have only 4 eggs retrieved is really disappointing. All the blood draws, all the ultrasounds, all the stress, all the money...just doesn't seem fair and doesn't sit well with my heart. I'm worried.