Difference between Lunar months and regular months?

Question

I will be 20 weeks next week, so I was reading my pregnancy calendar and it said that I will start my 6th lunar month at that time. But I thought that 20 weeks was 5 months. Can anyone tell me the difference between the two and how they are calculated?? PLZ HELP Thankyou.

So at 20 weeks I will be only 5 months correct???

Answer 1

regular months and weeks are as follows:
month one = week 1-4
month 2 = week 5-8
month 3 = week 9-13
month 4 = week 14-17
month 5 = week 18-21
month 6 = week 22-26
month 7 = week 27-30
month 8 = week 31-35
month 9 = week 36-40

for lunar months each month is 28 days

note also that even with regular months your due date is the last day of your 9th months (not the first) and that a term pregnancy is 37-42 weeks (not just till 40)

Answer 2

A lunar month is 28 days or 4 weeks, from one full moon to the next. A calendar month is 30/31 days or 4 1/2 weeks. A normal pregnancy last about 9 calendar months or 40 weeks which is 10 lunar months.The half weeks in each calendar month make up the 10th lunar month.