unsure

Sooo I haven't had a period all month, it was supposed to start April 6th and has never shown up. I have taken over 4 pregnancy tests and all have been solid negatives. I had this happen last year in October where I didn't have a period all month but got negative results every time I tested and then my period started on time the next month. I'm debating on going to the doctor and getting a blood test done but I don't want to be disappointed...but at the same time if something is wrong I need to find out what it is. I'm just scared it will be something awful...