M.G.
To me it sounds like you are either adjusting to the hormones, or it's not the right method for you. It can take 3 -6 cycles to see if it's a good fit (that's how they used to explain it to me) and I went through a lot of trials before settling on birth control in my 20's. It was the same for my friends. I sometimes was bloated, gained weight, felt sick, tender boobs, bad skin, you name it.
I would go and get tested just to put your mind at ease, and keep a log of your symptoms and your period. Some people keep track of when they have sex too.
When I was pregnant, my breasts were veiny. I don't remember so sore I couldn't wear a bra. My morning sickness (with one child) was consistent and not here and there. I didn't feel very bloated and my back didn't hurt (not until I had quite a belly). I'm very small, and even so my stomach didn't really pop until quite far along. I remember hoping it would. So I can't relate to what you're describing - that reminds me more of feeling hormonal.
If you just had it removed, remember, now your body is adjusting all over again. Hormones don't just affect your reproductive organs, but also your brain (they can give some women migraines, even the kind without headaches, which can leave some women nauseous etc.).
Good luck :)