2 missed periods,on the pill,neg preg test but strange symptoms

hi I've been on micronor pill for about 4 years and never missed a period although they've always been irregular. I've now missed two periods, done hpt and it was neg at first then within 30mins a faint positive line appeared (it was an early detection one so says within 30mins the test could change but if it's after 30mins ignore any change). I went docs as wasn't sure how to read it, urine test at docs came back negative. But im still not happy, I keep feeling queasy,got more discharge than normal, crampy pain as if I'm going to come on,but I don't and get a heavy pressure feeling low down in my stomach which I don't normally get. Also,I don't know if I'm just reading too much into stuff now but the last couple of days i feel my sense of smell is more sensitive. I'm back at docs Tuesday cos something is going on,just clueless to what it could be. Anyone any ideas please?? Or has anyone had the same thing?