Hello and welcome to HCM.
Thank you for your query.
I would first have preferred to know whether this is the first time your periods have been irregular/delayed, or you have always had irregular periods
. If so, then you should wait a while longer for your period. If not, then this could certainly indicate some underlying condition.
Now commenting on the i-pill. This is a very effective contracceptive, which has to be taken within 72 hours of the sexual act. Its efficacy drops as time passes and is deemed ineffective after 72 hours of the sexual act.
It is 98 % effective if taken within 24 hours of the sexual act
It is 85 % effective if taken within 25-48 hours of the sexual act
It is 58 % effective if taken within 49-72 hours of the sexual act
As you can see, although you have taken the pill, its efficacy cannot be predicted. Now coming to the side-effects, yes the pill can at times result in menstrual irregularities.
tests are reliable, but have to be taken at least 2 weeks after the sexual intercourse. For some women a pregnancy
is undetectable till 3-4 week after the initiation of the pregnancy as well. So if your tests are negative even after 4 weeks since your last sexual act, then you are not pregnant. This could just be a side-effect of the pill, and your period should normalize from your next menstrual cycle.
I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications at: http://doctor.healthcaremagic.com/doctors/dr-shoaib-khan/64581 . I would gladly help you.