Negative Pregnancy Test, Delayed Period, Egg White Discharge. Any Inputs?

Hi, I am 18, and am not 100% sure if I am pregnant. I have taken 3 pregnancy tests (the last one I used morning urine and it was after my peirod was supposed to come) and all have been negative. However, I am not certain of the result because I have not had a period in over a month. My last NORMAL period was late June, I didn t have one at all in July (I was under an immense amount of stress and took a 10 day cruise), then I had a very late light period Aug. 5- 10... it was much lighter than normal, though. I haven t had a period since. My weight has fluctuated and has been a bit on the low end (92-96 lbs), but I never lost more than 4 pounds. I am in college now and have had almost a month to adjust, but two weekends ago I was a wreck emotionally and last weekend I had a cold . I know stress can affect ovulation , but I am really not certain about the negative pregnancy test. I have had egg white discharge for about a week now (lots of it), I think that I would get more than most people as my period approached, but I know it is also a possible sign of pregnancy. Any input would be appreciated, and I will see an OB GYN in early to mid October but am stressed and would like some input now if possible.