Congrats! You can read up the thread in this forum on the Obst & Gynae for recommendations.
You can visit the gynae anytime after you've tested positive. But most mummies would prob advise you to go after 6 weeks cos' too early the you/s scan may not be able to detect the heartbeat and this creates unncessary worry and paranoia. Of course this is provided you are feeling well and no major discomfort so far.
(BTW I'm expecting my #3 and was already 10 weeks when i saw my gynae. The nurse was like giving me the 'you're unbelievable' look. :-P)
Can start on folic acid first while you decide on the gynae. Good luck for the baby!