Positive test. Now what?

So I took a pregnancy test this afternoon after I got home from work. My breasts had been tender for over a week and I'd had lower abdominal cramps for about a week. Period is 6 days late today. What do I do now? We weren't TTC.

I was diagnosed with PCOS and hypothyroid years ago so it was quite the shock.

Should I take another test? Should I call a Dr. to make an appointment? We're not telling family or friends yet so I have no one to ask and I feel like I'm in over my head!