Can I Have Heart Palpitation Due To Contraceptive Pill Or Iron Pill ?

I would like to know what are the causes of heart papiltations and if they can be serious? for the past 3 days my heart has sometimes felt like it has skipped a beat, it feels like one or two beats are a bit slower than they should be and it gives me a funny feeling in my throat as well as shocking me a little and it also really scares me. i had the same problem about 6 months ago only for a couple of days but this has been tonight, last night and also quite frequently on saturday night. on saturday night i was drinking alcohol which i havent done for a while, i dont know if this would have made it worse? also i am slightly anaemic but take iron tablets, and also i take the contraceptive pill (but have taken it for about 1 and a half years) if either of those things might be causing it? sometimes i also get shortness of breath and i have experienced slight chest pains before but that stopped quite a long time ago and the doctor said at the time it may have been related to the pill, but said i could still take it later on. does anybody know what it might be please?