My husband and I have had several children and tried many standard pills which caused adverse side affects. I've been on this triphasal pill for a month and as yet my period hasn't started. I generally have a clockwork body that rarely is late. I'm now day 5 of sugar pills with no sign or symptoms of getting my monthly friend. pregnancy test was negative this morning but I know it would still be early for mid stream tests to possibly show. is it possible that I have fallen pregnant again due to the different incrimented hormones, or is this common for triphasal pills?