Ovulation and Irregular Periods !!

I've been Diagnosed with PCOS , and I was on Birth Control to Regulate my Cycle , for less than a year and recently quit ! I've been off for about 2.5 Months . My Parther and I are trying for our First . With having Irregular Cycles it's hard to know when I actually Ovulate . My last Period was Janurary 1st - 5th . This App shows that my Fertility Window is from Janurary 13th - 15th . We had Unprotected Sex on Jenurary 12th and 14th . He did Ejaculate inside . We've tried once and didn't Concieve . What's the possibility of Actually Concieving now and how to know if this is Truly my Fertility Window ! I Need Help ASAP !