Question: Hi, Would like to Know how to reduce side effects of i-pill ? -taken on 12th feb.

I am 32 had sex unprotected on feb 12th and my periods started that day itself 12th until 14th feb ..took an ipill (first time) to be extra safe within 24 hours.. and on 1st march had spotting brownish (1day only) and past 4 days feeling nausea, abdominal ( left mostly) discomfort its only 3 weeks now ( from 12th feb) and I did take home pregnancy test - it showed negative. my periods is usually 30 -33 day cycle but was delayed this last cycle as I had a lots of physical work+stress in an event we organized dec [ last period dec 25th -next feb 12th only] I read online that ipill side effects is also spotting/bleeding between periods and few others had nausea too My question is what do I do to reduce these side effects - nausea and abdominal discomfort.? How else can I be sure am not pregnant --its only 3 weeks and seems like I have to wait 4 or more weeks , is it ? My current test is negative. Thank you so much for your reply..