Late blood test results? Kind of worried they found something?

I haven't had a period since December 24th, I went into the health care center in March to get checked out, they gave me a urinary pregnancy test that came out negative and then told me that I need to eat more. I thought whatever and went home and started my new high calorie intake diet. I went back May 4th because I still hadn't had it (they told me to come back within 1-2 months) they drew my blood this time. They didn't tell me what they were testing for but after they took my blood they gave me the sheet and hormones LH, FSH, TSH, Prolactin, were tested along with another pregnancy test, this time blood. It'll be 3 weeks tomorrow since I had my blood drawn and I still haven't gotten the results back. They send the blood to a hospital in another town not too far from there. I've gotten blood taken from them in the past and got the results back no later than a week after my blood was drawn. I've had my blood taken loads of times from many different doctors and it has NEVER taken this long to get them back. Even my paps-mere results from them didn't take this long. Maybe I'm just paranoid I don't know. I have HPT's at home but I don't feel like wasting them because I know I'm NOT pregnant. Granted I was having unprotected sex for a few months but after I stopped having periods in December I started using protection and have been ever since. I think that if I was pregnant I would've known by now. I think it has something to do with my hormones. I've always been underweight because of my extremely fast metabolism. I have to consume over 2,000 calories a day just to gain a couple pounds. I've been following their advice and keeping a food diary and writing down all the things I eat and the calorie intake I get (I feel like they are treating me like I'm freaking' anorexic or something). I have been putting on a little weight and my measurements have been getting larger which I am very satisfied about but I was having periods every month till December. If it was because of my "weight" why would it all of the sudden just stop? What I'm asking is does having test results that take a long time to come in mean they have found something and are doing further testing? Or am I just paranoid?