I've Been Taking Benylin 4 Flu For About A Week,

I've been taking benylin 4 flu for about a week, four doses a day to start reducing to two, when I reduced that I took Exputex as was getting a chesty cough. I'm also on Yasmin, which I started taking two days ago, after my week break. I have a really bad stomach now, is it because of all this medicine or could it just be a bug?