What Causes A Delayed Period,tender Nipples And Stomach Bloating?

my periods are regular every month 28/29 days lasting about 5days. however my last period only lasted 3days took a pregnancy test this was negative. i was then due for next period on the 18th march but still waiting. i have taken another test but again this was negative. me and my partner are trying for a baby and i am alittle worried as my last pregnacy was ectopic and resulted in me having my right fallopian tube removed. i have been experiencing tender nipples and am bloated, was sick one day last week. also i had a smear test done the day before my period was due could this delay my period hope you can help hayley