to find out how many weeks of pregnancy

For many pregnancy kits, the result will only be accurate about a week after you miss your period the next month, when the pregnancy hormone level is high enough to be detected. That’s why you had multiple negative results. When you count your pregnancy estimated dates, you still use your last menstrual period date. But the scans will have a more accurate date. Now that you’re coming to 12 weeks of pregnancy, you should see a gynae soon and get a dating scan done:)

If you haven’t gone to see a doctor, you use your last menstrual period to estimate the dates. So, today, 3 March 2020, your estimated gestational age of your baby is 11 weeks and 2 days, and your estimated date of delivery is 20 September 2020. You should go see a doctor and get a dating scan done though, because the actual dates can be quite different sometimes

Actually you can get a Clearblue digital test kit. It tells you how many weeks from conception you’re are at till week 5. After week 5, it will show as week 5+. Guess it’s probably cheaper than seeing gynae and can do 2 things - test for positive and confirm estimated weeks.