Italian Sausage still a little pink? So im a little scared, I was cooking some italian sausage links on my cast iron skillet. 

I cooked them 8-10 min a side on medium , then turned to low and cooked 7-8 minutes a side.

I checked the temp on the very middle and they all registered about 170 degrees (This was after they had been on low, at the very end)

Anyways I ate them, tasted fine etc...

But upon eating another one later, I discovered that there was still a pinkish color in the middle. (More towards the edges). It wasn't a lot....but the thing is I know this thermometer is accurate and I always use it.....Plus I cook them like this all the time. So I didn't understand why it was still a little pink on the inside. 

Just for reference I stuck the thermometer on the inner most part, I made doubly sure. And they were all checked and all were 170-180 after they had been cooking on low (So it was prolly a high temp earlier when they were on medium)

Any ideas? Im kinda scared. For reference these were Sweet Italian Sausages (not sure if that would matter)
The salt treatment in sausage can cause it to retain a pinker color for a given temperature than would normal ground meat.   The fact that you used a trusted thermometer, and that the sausages were well in the safe zone (even conservatively 165 F is more than enough) indicates that the sausage was perfectly safe.