Don't worry. Inf anything buy more. ABT is one of the steadiest stocks in the market and the spinoff makes it an even more attractive investment. ABT now is essentially JNJ at tremendously cheap valuation. Just sit tight and you will be rewarded.
I have owned ABT since 1961, therefore I know this company like the back of my hand. For the last 38 quarters, the day the earnings were reported the stock has been down. There is great euphoria, when earnings are announced, and then as Ponty says, the fine print comes out about 2 hrs. later, and then the stock drops. It looks like it may be true again today, but don't panic, ABT always does well in the long term. If I kept all of my shares from my $3,000 investment in 1961, it would be worth about $6,000,000 today.