Hi Karen
My cheery surgeon told me I would have lost of twinges and funny sensations after my mastectomy and I was simply to ignore them. I did both. They vanished after a few weeks, although they were more of the funny sensations and twinges type than actual pains. I do still get an occasional twinge, from the scar tissue - not painful, just feels like an odd stretched muscle at times.
You can get some fluid, which may be what the trickling feeling is. It should dissipate, but keep an eye on it and ask for advice if it doesn't.
I lost a lot of feeling in my underarm - initially it felt like someone else's altogether which was a bit alarming, but gradually feeling returned. It's still not perfect, so possibly never will be but the only real impact is that I can't feel cold deodorant on a really cold morning and probably should never use hot wax on my underarms!
Good luck.