18 weeks pregnant how many months not to sure?

Think in weeks: We discuss everything about pregnancy in terms of weeks as it is much more precise than months. A pregnancy is 40 weeks (10 months) long from the first day of your last period to your due date. Most people don't find out until they're late for period or about 4-5 weeks along. I'd recommend you try to think in terms of weeks as that's how your provider will discuss your pregnancy.

4-5mo gone/4-5mo 2go: In OB we prefer to go by weeks for more precise dating and better evaluation of fetal growth, etc. There are 40 weeks from the first day of the last normal period to the due date. So, at 18 weeks, there are 22 weeks till the due date. I hope this helps.