I have been taking cerazette since Spetember 2012 - I had a period early October 2012 and one late November. At New Year I had a tummy bug which, in hindsight, made the pill less effective. I was also more than 12 hours late in taking a pill. My partner and I had sex on New Years Day and again last weekend. For the last week I have been experiencing nausea , dizziness with dull headaches , slight cramping, tender nipples, and constant need to wee. I have taken 2 home pregnancy tests and have come back negative but the symptoms I am experiencing are similar to those when I was pregnant with my son (5). Can cerazette provide a false negative result? I wouldn t even know where in my cycle I am due to not having periods. Am I too early to be taking a hpt? And if I was pregnant, what would eb the effects of taking Cerazette whilst pregnant?