Taking a higher dose of clomid and still not ovulating

I started out on 100 mgs of clomid it didn't work doctor but me on 150mgs still not ovulation used the strips. what is the highest dose a person can take. I was lucky I concieved my daughter only on 50 mgs and it only took me 2 months. But I have gained some weight since than about 10 years ago. Also should i just reley on the ovulation kits to see when i ovulated and if it is my fertile period and they still come back negative should i still have relations with my husband. thanks