I had botox once approximately 3 months ago for the wrinkles when I frown. It is now starting to wear off slightly and I have noticed a prominent vein on my forehead. Is this caused by the botox? I am now really concerned to have it done again as I really don't want a noticeable vein. Also since i had botox my skin looks tight between my eyebrows. Is this because it hasn't been done properly?