I'm in a pickle, need some advice/help?

Today makes me 5 days late for my period (that usually always comes on time), I took a pregnancy test yesterday morning which turned up negative. I also had a really short, one day period last month, had urine and blood tested for pregnancy, both negative. I then had cramps for a whole week or more after the one day period. This month, nothing, not even spotting. I'm starting to have a lot of pain in my mid-lower, back, my boobs don't really feel any different they what they normally feel around AF. I've noticed my hair is starting to fall out, I would describe it more like shedding. I am sexually active and my boyfriend uses the withdraw method so I know there is a chance that I could be pregnant any month. I am really confused as to what is happening in my body. I know they say that stress can do that to you, but I don't think I'm really any more stressed out than normal. I've been getting pretty emotional lately, so every morning, I jump out of bed and go to the bathroom to see if I've started. What should I do? I don't have insurance, at the health department they wanted me to get an ultrasound but I can't get in touch with the hospital on my work schedule. Please help, thank you for taking time to read this. I'm starting to get nervous.