I'm exclusively breastfeeding but trying to get my baby used to a bottle for when I go back to work. He's 6 weeks old. I started with the calma and he hated it so I tried NUK and tommee tippee- he hated those too. So I'm back with the calma having read brilliant things and being told you have to work at it. Does anyone have any advice? He screams blue murder every time we try. He took it once (drank the whole bottle) but that's it- we've tried at every feed today but he won't have it. I really love the idea behind this teat as it's supposed to be so similar to the nipple- would love to have some success!