My last period was 4 days long & its usually 7. normally i would be ovulating or fertile by now but i am not and my cm is watery. could i be pregnant?

Maybe. Maybe not.: A urine pregnancy test done correctly gives a reliable result 3 weeks after sex (3 weeks after when conception might have happened) or a few days after a "weird" period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and therefore lead to a repeat test. If one has her normal regular period, then she is not pregnant, and a test is not needed.