I wonder if you accidentally bought the cultivar
‘Treneague’ , which was developed for chamomile lawns. It doesn't bloom.
Other than that specific cultivar, Roman chamomile blooms late spring to summer. Yours might just be a little slow, since you just planted it. I would give it another 2 to 3 weeks, I think.
In my yard, chamomile is a weed, and it isn't blooming yet.