Hello,
There is no chance of being pregnant in that type of sexual activity.
Pregnancy is possible only, if unprotected sexual intercourse is done with ejaculation around ovulation time in regular period.
During excitation/arousal, vaginal secretion is common and natural thing. Here, you have nothing to worry. Slight brown discharge is nothing significant if there is no bad smell or itching.
Painful ovulation with other features may be associated with pre menstrual syndrome (PMS).
Avoid salty food/coffee in 2nd half of period, Avoid
stress by yoga/deep breathing, Control body wt, Take healthy diet, wear tight breast support, maintain genital hygiene and need proper sleep.
For direct consultation with me, you may visit my profile on http://www.healthcaremagic.com/doctors/dr-soumen-patra/63326.
Be well and take care.