Thank you! I have been feeling very uneasy about this and my gut feeling is that this situation is not kosher. I am scheduling a sit down meeting with the HR director to have her manually enter me into the system per my contract. Thanks for the advice!
"Since it should have started March 1st (and through no fault of my own but rather because of my employer I was not signed up then) this cannot be considered a pre-exisiting condition? "
Unfortunately, the fact it "should" have started on a certain date is meaningless - the insurance company goes by the actual date your policy is instated.
Also, some insurance companies don't consider pregnancy a pre-existing condition - thats something you need to look into with your specific policy.
I would pay your HR director a face-to-face visit and explain you are not comfortable not having health insurance - there is no need to go into any details, that it is none of her business and "may" complicate matters. At the end of the day, you were told your insurance would kick in by a certain date and it is very inappropriate that it has not. If you don't get any immediate action (it shouldn't take her more than 20 mins to take care of this) I would then approach your supervisor and express your concerns regarding this.
Pregnancy aside, a similar thing happened to my husband - he was told he would have insurance on a certain date and had canceled his previous plan accordingly. Needless to say the HR department did not get there act together, he broke his ankle and we now owe $20,000 in medical bills. Not having health insurance can be VERY costly in the USA which is why this situation is highly inappropriate and warrants IMMEDIATE action.