Routine Checkups and Tests in China

Hi Rameesha! It's going to depend on your doctor and your situation. For example, someone that has an erratic period and/or didn't know when they became pregnant, they would verify by sonogram. Keep in mind that dating by sonogram is only accurate before about 10 weeks (ideally 8 weeks). Sonograms are very affordable here and so many times they will automatically schedule you one.
That being said, it's going to vary by doctor and hospital which method they will choose to use. If you know that you do not have a 28 day cycle, it is a good idea to discuss with the doctor alternative ways to get a relatively accurate due date. Many times they will recommend an induction between 39 and 40 weeks of pregnancy, and they will definitely want you to birth the baby before 41 weeks, so if your conception date is off by more than a couple days this could influence those decisions.