Endometriosis & Poly Cystic Ovarian Syndrome (PCOS) are common causes of irregular periods. Irregular periods also indicate mild hormonal imbalance & anaemia & this does not prevent a person from concieving. If your menstural cycles are ovulatory (fertile) & not anovulatory then the chances for pregnancy is good. Painless periods indicate that your cycles are anovulatory in which case ovulation inducing drugs like Clomiphene citrate will help. You can plan your pregnancy if your cycles are ovulatory. In ovulatory cycles ovulation occurs 14 days prior to the onset of menstural cycle. Chances of fertilisation during ovulation period is very high. Slight morning rise of body temperature indicates ovulation & 7 days after that is a fertile period. But Brenda, before you proceed, you have to rule out the causes of infertility mentioned here & correct anaemia otherwise the chances of success is minimal.