Could missed periods signal a medical issue?

It's good that you are taking steps to recognize things early. Dexamethasone is used to help a baby's lungs develop in case they are born prematurely. Premature means the baby is born before 37 weeks of pregnancy. You don't need to worry about the baby having problems with this medicine if they are not born until after 37 weeks.

Aap ka concern samajhna zaroori hai. Pehli baar intimate relation ke baad halki bleeding aam tor par mukhtalif wajah se hoti hai, jese ke vaginal tissue ke khichne ya injury ke karan. Ye aam tor par kuch din tak chal sakti hai. Agar bleeding zyada, dard ya dusre unusual lagne wale symptoms hain, to doctor se mashwara lena behtar hoga. Ek gynecologist aap ki achi tarah guide kar sakta hai aur koi bhi necessary tests kar sakta hai. 

You might be dealing with some tearing in the labia minora of your vagina. This can happen due to the past activities of masturbation. It is important to look for any color or texture changes. Black color could mean some healing tissue. As long as there is no pain or discharge, it is probably not dangerous. Keeping the area clean and not giving it any more irritation should help the healing.

When periods are delayed and prolactin levels are at 28 ng/mL, it may be due to a condition called hyperprolactinemia, which is characterized by high levels of prolactin in the blood. Symptoms can include irregular periods and milky discharge from the breasts. This condition can be caused by stress, certain medications, or a benign tumor on the pituitary gland. Treatment usually involves medication or addressing the underlying cause.

Maybe it seems like you've got a small tear or cut down there. This is something that happens to girls sometimes, especially while on their period and the part is most sensitive at this time. It should get better in a while without any medical intervention. As long as you are gentle and take good care of that area it will get better.