Strange feeling

Has anyone been going about their normal day and then all of a sudden they get this feeling like something is wrong. And they are not pregnant anymore? That happened to me today. I’m 7+2 today and I don’t know I just feel like it’s over. I don’t know if it’s just my nerves after everything I have been through or what. My OB visit is Tuesday morning. I’m going to wait it out till than. That might have something to do with it. I’m just worried. I really want this baby to work out this time.