8-10 weeks and still NO PERIOD

Hi. My husband and I have been trying to conceive for about 3 years now with no luck. I have one other child who's 8 and I did not know I Was pregnant with her until 4 months through a blood test. I did not have any pregnancy symptoms with her prior to knowing I was pregnant nor did I have any pregnancy symptoms while pregnant with her other than my belly grew a little. :-) My husband and I are both 26 and in normal health. We do not have insurance so we have not been able to see a doctor to determine infertility, etc. I was on depo for 9 months back in 2002 and bled every single day for 9 months straight. The dr at Planned Parenthood said it was normal, but I did not think so and did not go in for the 4th shot. This was the only time I've ever taken birth control. I went to my gyn and everything was normal other than low iron from the excessive bleeding. It has now been 4 years since then and ever since then my periods went back to normal, every month. My cycle is about 30-32 days long (I'm not a counter) and usually lasts 5 days, light to moderate flow. Over the last few months, my cycle has been late by a couple of weeks (probably stress) and bled heavily for about 10 days. Now, the last cycle I remember having was around June 24th (I remember because my friend's wedding). Since then I have not had a period. It has been anywhere from 8 to 10 weeks since my period. I took 3 pregnancy tests over a course of a week & half a few weeks back, but they said negative. I am not doing anything out of the ordinary and I'm not feeling stressed out (actually have been at home on a break for about 2 months now relaxing). I have been SEVERELY TIRED where I just can't get out of bed for the last month - and I've been going to bed at a normal hour. I have been going to the bathroom more than usual. Usually I only go once or twice a day but now more like 5 times and I'm not drinking excessive liquids. Sometimes I have headaches and I feel very gassy over the last few weeks. Also, sometimes I would feel some kind of movement in my lower body, not a gas feeling because I obviously know what that feels like, but maybe I'm just fooling myself and remembering stretching from my last pregnancy 8 years ago??? Anyway, I've come to the conclusion that I'm infertile or something since its been 3 years now so I DREAD going to buy my hundreth HPT test only to be let down. I am worried though considering it has been so long. Maybe I have some kind of disorder or something? Which is odd because my family is healthy. The other times my period was late only by a week or two due to stress most likely. But its been 8-10 weeks! Is it possible for body to not register hormones at a high level for HPT to detect when someone is this far along? I did have this trouble with my 1st pregnancy as I mentioned above and had to do blood test at 4 months. I just had a feeling one day when I was helping my granddad cut fire wood and I got sick a little and felt dizzy from pulling the trees around front. Even then another doctor who did an ultrasound said my baby was only 10 weeks old and he was WAY off (maybe because she was a small baby being asian?) Anyway, either way I have some issues going on here and really need some advice. Remember I don't have insurance, so I'm debating on just waiting it out another month to see if I start feeling any other movement since it would probably happen in mid Oct. before I go to the doctor. Any advice on what might be going on other than a pregnancy would be great (although I really do hope it is pregnancy!). Thanks and sorry for the long post. Worried and discouraged, Mindy