getting worried

I'm 15weeks +5 and I'm getting anxious that nothing is happening . I misscarrid back in November 2016 so I think I'm just being paranoid but I just can't get it out of my head that what if ... I can't speak to my midwife as she is part of my drs surgery and it's a weekend so she isn't in and she hasn't given me a number for her . I need some reasurence. I am seeing her on Thursday this coming week but I have exams on and just getting to the point I'm constantly stressing and worrying . What should I do , shall I wait till Thursday  ? Or ?