I would say she probably doesn't have an upset tummy from too much milk... babies tend not to overfeed themselves. Although perhaps she has wind which is making her uncomfortable?
The best way to see if she is still hungry is to offer her the breast again and see if she wants it?

With the tummy rumbling - this will not only be an indication of hunger or upset tummy, because everyone's gut actually makes rumbling noises nearly all the time - this is just normal movement from digestion.

It's really hard in these first few weeks to work out what is going on for your baby... you are doing a great job though Veronica! Let us know how things go...

(sorry I'm not more of a help, its been a while since I had a newborn!!)