I Had A Skin Test To See If I Was

I had a skin test to see if I was allergic to nuts. It came out negative. But I had to reactions to a shampoo that contain almond oil. I had rash and hives all over my body and had to go the the emergency room. Since we did not know what cause it the following day I use the same shampoo and had the same reaction again. So I know the almonds are affecting me. But now I am confuse since a previous skin test was negative.Am I allergic or not?