I spent the whole first half of pregnancy wondering so I finally looked it up. Since the weeks and months don't *quite* line up, you should divide weeks by 4.3. There's roughly 30-31 days/month but only 28 days for every 4 weeks. That's why we say 9 months of pregnancy even though it's 40 weeks (which feels like it should be 10 months).
Long story short, you're 7.2 months along! Congrats!