Causes of Missed Periods

Yes, you can get pregnant after your last menstrual period on 16 Jan if you had an intercourse on 8 Feb, the chances of which largely depend on the timing of the ovulation and menstrual cycle regularity. If you have any worries about pregnancy or reproductive health, then please see the gynecologist for an examination and tips.
 

PID is an infection of the female reproductive organs, usually caused by STIs like chlamydia or gonorrhea. However, PID can also be caused by non sexually transmitted infection, like bacterial infections, medical procedures, or bacterial imbalances. Regardless of sexual activity, PID requires medical attention for proper diagnosis and treatment.

It seems you may have le­g muscle pain before your pe­riod. This is common for some people. The­ pain could be from hormone changes in your body be­fore your period starts. To help e­ase the pain, try gentle­ stretches, use a warm cloth on sore­ spots, and drink lots of water. If the pain gets worse­, be sure to tell me­ at your next visit.

Yes.. it's possible to use contraception while engaging in sexual activity, regardless of whether or not you are experiencing depression. Contraception is an important consideration used to prevent pregnancy..

Painful headaches, vomiting, and pale face during periods - common. Vitamins and folic acid may not work. Consult a doctor immediately. 

Menstrual migraines can be caused by changes in hormones and dehydration. Over-the-counter painkillers are generally safe to take for a headache but make sure it is suitable for use during your period before taking anything new. Always follow the directions on over-the-counter medication or ask a pharmacist which ones won’t interfere with menstruation.