Hi, I returned from India on 15th February and took Malarone as I was in Goa for 5 days. However I stopped this medication when I arrived in Goa as I was experiencing horrible side effects (feeling sick, dizzy, generally unwell). When I stopped taking this medication the symptoms stopped. However today it has been 40 days since my last period. My periods are generally irregular anyway, but I have been 40 days, the longest I have waited is 37 days. I took a pregnancy test last night which was negative. I wondered whether this delayed period could be because of the Malarone and/or travelling/disruption to what my body considers normal?