When do you know?

I read the post below and it said to insist on a test if something happens longer than 2 weeks. I am still on Herceptin every 3 weeks, so I keep telling myself, it's just in my head. My masectomy side arm is numb and tingly going on 2 weeks and I called my onc and told her about my breast bone having a spot that hurts and the area over the masectomy feels like I burned my skin, it is very tender to the touch and a little warm. I have no rashes and the pain in my breast bone area is getting bigger and I feel it above my sternum. She said to take ibuprofin 800mg daily for 3-4 days and said it was probably the muscle tightening up or scar tissue. I finished carbo/taxotere/herc on March 29 and rads on June 1st. How long does it take for a body to recover from the chemo drugs or to differentiate(sp?) between a reoccurrance. I just had a muga and it was at 60. Have any of you had a reoccurance while on Herceptin for first time bc? Can this happen?