possibly pregnant?

Abby
Hi so I haven't had sex in a while maybe a month and I take the shot for birth control. I haven't had a period for almost 2 months now. I have gained a lot of weight 10 pounds actually in the past month or so and I don't eat much and I have a fast metabolism so I never gain so much weight ever. I'm at my highest weight at 141 pounds. I have been experiencing some sharp pains in my stomach and intestines areas. Idk if it's because It's just allergies or if my uterus is expanding. I've thought I was pregnant about 22 weeks ago as well and I took many pregnancy tests and they were all negative. I'm looking for some help. I also haven't been able to sleep much because this sharp pain has been keeping me up. I just started working Monday and it's only gotten worse. I drink enough. I have no problems with the restroom. I have major headaches. Help. And I also have a lot of white discharge. But again I don't have periods so I'm confused.