dreamababy,
sorry for late reply.....the pregnancy calculator is a good tool if u want to track how many wks u are pregnant base on your input on LMP, mens cycle plus it will also calculate for u your EDD. however we can't gurantee that our ovulation is on the dot so after a couple of scan, your gynae will advise u on your new EDD and confirm with u how many wks u r pregnant. ie base on the size of your gestation sac, yolk sac etc.
As to when you want to see the gynae, it all depends on individual. for ladies who experience little/no discomfort and no spotting problem, they may see the gynae at 7-8wks because that's when u should expect to see fetal pole and heartbeat. any earlier, u will only see the sac. however some ladies would want to go early to make sure that everything is fine and to start taking folic acid which the gynae will prescribe. u can get folic acid from the pharmacy so it is advisable to start taking once u know u r pregnant. I know that some ladies take it when they are planning for a baby.