Can I stop periods to be intimate?

there are SEVERAL reasons for delayed menstruation in teenage girls. Puberty timing varies widely. Hormonal imbalances can delay menstruation. Excessive exercise or underweight can impact menstrual cycles. Stress or medication can also delay periods Consult with a DOCTOR.. 

Its a rare congenital condition that occurs during fetal development. Generally most congenital abnormalities including penile agenesis are not preventable. They can result from a combination of genetic, environmental, and developmental factors that are often beyond our control.
It is also important to seek emotional support and counseling to address the feelings and challenges you may be experiencing.

After taking methotrexate , you have to be careful with your Blood counts , check your liver function tests. Also patients commonly get ulcers in mouth , take inj folinic acid for same

Light red spotting after not getting a period for one month may indicate implantation bleeding, hormonal imbalance problems or complications to the pregnancy itself. It is advisable to see a gynecologist for proper medical checkup and also receive an accurate diagnosis. 

Masturbation does not cause pregnancy. Check with your gynec for your periods.