Am I protected from pregnancy if I vomit about 2 hours after taking yaz? I vomitted after drinking a bit too much at a party on the 12th of august. It was a small amount of throw up but I did not realize that vomitting could weaken the effectiveness of b

Even. Even if you hadn't vomited oral contraceptives are not 100% effective. In practical usage the rate is 96-98%. Practical usage incorporates factors such as missed or late pills. In your case if you had taken all the other pills you are likely in the 96% proctection range. From the date of your question I suspect you know the answer to by now. Please let us know.