Thank you for reaching out to us.
This is an excellent question, and there are varying halachic opinions.
Our current Rabbinic Supervisor, Rav Kenneth Auman, maintains that ovulation is not close enough to the start of menstruation to be halachically considered a
veset haguf, a
veset based on physical symptoms. Please see our page on
veset haguf for a detailed discussion.
According to this opinion, although it is not a
veset day, and there is no halachic requirement to abstain, we would recommend refraining from actual relations on that date as a precaution.
Other Rabbanim, including our founding Rabbinic Supervisor, Rav Yehuda Herzl Henkin ztz"l, and current Nishmat Rabbanim Yaakov Warhaftig and Assaf Bednarsh, do consider clear signs of ovulation to be a
veset haguf. That is the opinion cited in
Nishmat Ha-Bayit, available
here in Hebrew.
If you follow that opinion, you would need to track the onset of your ovulation pain (daytime or nighttime and Hebrew date), as well as the onset of your flow, over the next few months. Once you have this information, we can see if it suffices to establish a
veset haguf, and discuss what that would mean in practice.
Behatzlacha!
