What can be going on? Pregnancy? Help me please?

I'm almost 5 months late on period and at first I didn't think nothing cuz I've been late before but 3 months max never almost 5 so I took a pregnancy test and it came back negative. No I'm doubting it cuz I'm gaining crazy amount of weight, I'm always hungry like ALWAYS, I feel immense pressure on my stomach when I lay on it, I get weird pains, and I just got a yeast infection (gross I know) but I have never had one before. I've had no pregnancy symptoms either so idk if I should go to the doctors or not?? Any one go through this?