When should I call the doctor?

So, yesterday morning I slipped and fell down the stairs. It may just be a coincidence but, ever since then, I haven't felt my baby move at all. I can usually feel flutters through the day or movement but, ever since then, I haven't. I've also been having cramps and sharp pains in my abdomen. The cramps are similar to period cramps. I've also been feeling nauseous, which I haven't since I started this month (🙏🏻🙏🏻) Then, just a little bit ago I had a little diarrhea.

My boyfriend is freaking out but I keep telling him not to worry and telling him I'm fine because my worrying will only make his worse.

Am I being paranoid or should I go to/call the doctor?

(PS I'll be 15 weeks tomorrow)

EDIT: when I slipped, I fell on my back and slid down the stairs that way. I hit my head and my bum but I didn't hit my tummy)