How long until a cold sore isn't contagious?

I just got my first coldsore, my sister gave it to me. I took a sip of her drink and two days later i had a tingling/burning sensation. Instantly, I put abreva on it, and iced the crap out of it. I've also been taking 4,000mg of lysine. The coldsore never became a blister, its just a white spot on my lip (very small) but no bump. Doesn't tingle, hasn't since yesterday. when is it okay to share drinks/kiss etc? Thanks!