There are some things you can do for yourself without the help of a doctor.
Chart your basal body temperature (BBT). You need to buy a basal thermometer. A glass one costs about $5, but you have to wait 5 minutes before you get out of bed. For that reason, it is probably better to invest $10 and a B-D digital basal thermometer. These thermometers are more accurate than ones for fever, and accuracy counts for a lot! Once you have one, you should start taking your temp each morning at the same time, before you do any activity (speak, move around, get up, etc.).
Along with this, it is a good idea to chart your other fertility signals such as cervical mucus and cervical position. A wonderful book on the subject is Taking Charge of Your Fertility by Toni Weschler. There is a BBTchart spreadsheet available for download that is tailored toward conception (some fertility awareness charts are geared also toward contraception). You can also get charting software at
http://www.tcoyf.com and
http://www.fertilityfriend.com
Next, invest in some ovulation predictor kits. OPKs let you know ovulation is about to happen, while BBTs only confirm it after the fact. The OPKS and the Clearplan Monitor may not work for women with PCOS, and the saliva testers are less likely to work for large women. The saliva microscopes check for a ferning pattern that comes from estrogen, and overweight women often have high estrone (E1), which, while weaker than estradiol (E2), can still cause a ferning pattern in saliva or cervical mucus.
Take prenatal vitamins or the equivalent. A multi such as Centrum, combined with additional folic acid (make sure to get at least 800mcg) and calcium should be good.
Think about how you would eat if you were pregnant. Not so much in quantity, but in quality. Try changing your eating plan to be as healthy as you'd want it if your were pregnant, whether or not you are trying to lose weight.
Get informed. Check the web and newsgroups. Be an informed concern and an advocate in your health plan. Not only will you help yourself, you'll be better able to speak with your doctor.