First appt??

well i found out on Sat, My 9 month wedding anniv. that we are expecting #3, i believe i am about 4 weeks 6 days, i was wondering when they schedule a first appt with ob? I called and we go in for labs, then after the dr looks at my labs they will call us back with an appt. Ive never done it this way before bc i was 8 weeks when i found out with dd1 and about 6 weekd with dd2. so i dont know when i will be able to see the dr. also is it normal to have a very strong positive at 15dpo?? i took two test without holding pee once in the afternoon and the other at night and both showed up as soon as pee hit the line and the test line is darker than the control line. could it be i have alot of HCG or maybe multiples??