This is bullsh\*t and she really shouldn't be giving such advice.  Some women find testing for ovulation to be too stressful or whatever (which is valid - it does suck!), but it is impossible to get pregnant unless you have sex around ovulation.  If you have a regular cycle or are just lucky, then you might hit ovulation by having regular sex and not testing.  

I've gotten pregnant twice when I was not testing for ovulation.  My other 6 pregnancies have been the result of testing for ovulation and having sex accordingly.