Cycles can be affected by SO many things... not just pregnancy. Diet, working out too much, and STRESS.
If you are stressing about getting prego and working really hard on it, it can mess up your cycle like none other!
I know it is hard when people say relax about it, but it truly is real! I can't tell you how many gals I know that tried and tried and the first month they gave up- bam- prego and all was normal.
So just try and relax. You could very well be prego (I took a test for two weeks and it said negative, but infact I was prego), but only time will tell. Worrying about it won't change the result.
Your OB can order blood work without you having to set up an actual office visit, so why not call today.
Good luck... and remember take a deep breath and relax!