I have my mensural cycle as 24-26days. Today is my 28th day. I have not got my periods. But I attempted a home pregnancy test today morning which showed me negative result. But now for past 3 days I'am frequently urinating and there is an irritation on both my feet. What should I do further?

You need to wait another 10 days to take a test. You took it too soon. However, its really too soon for symptoms to manifest themselves.

What you should do is see your physician.