No, you can very well ovulate with little to no cervical mucus. However, cervical mucus is very crucial in conceiving. I noticed I never had cervical mucus but knew I ovulated as I used ovulation tests. I read online that taking robitussin a couple of times a day for about a week before you ovulate will thin your cervical mucus out. So after trying for a year I decided to try the robitussin & got pregnant the first try! 16 weeks & 4 days now. Worth a shot!