Realy bad first experience.

I have only been with medshield for one month and already i am unhappy and so stressed out. I changed over from discovery thinking it would be a better option. And then on the 15th may i found out i am pregnant, suposed to be an exciting time right? Well they sent a an email stating they will not cover my pregnancy! Not even a reason. Im assuming it is because im already 8 weeks according to the doctor. However i obviously was not aware of this when i joined otherwise i wouldv either mentioned it or not joined at all. This is realy upsetting and unfair as joined beginning of may and i did not even know i was pregnant at the time. I even took tests before the 15th and it was negative so how was i suposed to know? I realy would like this resolved before the 1st as i would like to cancel if my pregnancy is not going to be covered.