I started birth control one week ago, is this normal?!

It's totally normal. It actually takes up to 3 months for your body to regulate and become used to the pill (even though it's effective as a birth control after the first 7 days already). Nothing to worry about right now - even though it's annoying I'm sure.
But give it time and your body will get accustomed to the hormones and learn how to regulate itself.

Are you on Y az II ? mine did that on Y az and I had to quit after 3 months Bc of other things it did to me. my nipples were so raw from being hard all the time, they bled. They were not te nice hard that feels good either it was numbing like. they did come back after I quit . but I think I notice them more now an they still pokier in a flash. but at least now it is a good feeling down to the thighs. My VGA/ vulva swelled some times too. that is whY i quit. I looked ridiculous in Tights and I am a cheerleader.
I had always used spermicide for BC and to back up anything else being used . so I just continued my SX life with out PILL. and tried the IUD it does fine but sometimes I jar it out of position and have to readjust it. before Activity. .

Yes, it's caused by the BC and it is normal. Your body thinks you are pregnant and the hormones causes your breasts to swell a bit. It will most likely go away after a while.

Two side effects of birth control pills are both breast tenderness and retaining water. So yes it can be caused by the birth control. It's normal.