How can I truely know I am not pregnant? I am this overreacting freak like really. Only had sex with a condome, and I have had all my periods last one ended today, and I have had two home preg. Test and both were negative, BUT , I keep.gaining weight and I have this weird pains now and then in my stommoach. Is this just for eating unhealthy that this can happen or what ? What can cause the pain inmy stommach and the really really gaining of weight . I am eating unhealthy at the moment so that can be a factor.