Prickly Heat

I have herceptin n o7 last weds.Since previous one i have been getting a prickly heat sensation staring in my arms and then seeming to flush through my whole body,lasts about 5 mins I mentioned it nurse who just said keep an eye on it,but not sure if its a reaction to herceptin or the fact that I have not had a period since Oct.Going to GP next week ,but as ever any advice grateful