I know that I should just use a home-pregnancy test, but I need to know if it's worth it

I'm 16 years old, I've been having periods since I was 11. My mother and grandmother both suffer from some kind of endometriosis where they have irregular periods and I sometimes have that problem, it's normally 2 weeks, 4 weeks, 6 weeks, 2 weeks, 4 weeks, 2 weeks and so on. Recently, I started evening out, to every 4 weeks and I had been for 6 months. I've been sexually active for a year now, using condoms. I was on the patch for 3 months (when I started evening out), but suffered from weight gain, so I stopped. My periods were still regular though.

For some reason, between March 30th and April 4th (can't remember when, eeps) , my boyfriend entered me without a condom, but as soon as he realised, he put one on. It just happened to be the week I was ovulating. I was due for my period on the 10th, I have been getting cramping and small amounts of blood, but not enough for me to really consider it a normal period.

My breasts have started looking more veiny, I'm not being paranoid, my boyfriend agrees. I'm not sleeping properly, I keep waking up in the night with hot flushes and nausea. Sometimes I feel faint, dizzy and nauseous, but this only started yesterday. I keep wanting to cry for no reason, although, I suffer from depression, so this might not count for anything, but I've been a lot more emotional, my mood changes like this *snaps fingers*, example, sometimes I'm smiling, dancing, singing really happy and then something will happen, like my boyfriend going home and I'll just cry, I cried earlier because my cat wouldn't come in for his dinner. It's actually insane.