¿Por qué estoy hinchada con fuertes calambres y falta de período?

Missed PERIOD, stomach pain, and laziness can BE caused by:
-Stress or anxiety
-Hormonal imbalance,
-Polycystic OVARY syndrome
-Thyroid problems
-Endometriosis
-Pregnancy or miscarriage
-Uterine fibroids or CANCER
-Excessive exercise or weight loss
-Depression or eating disorders
-Perimenopause or menopause 
Consult a healthcare provider for proper diagnosis and treatment!!!!

The reason for the worsening of your periods and insomnia may be the hormonal changes from the surgery or the stress that comes with it. Period insomnia is a common problem that women face. You may also want to learn how to help yourself. Perhaps you could try some relaxation techniques like deep breathing exercises or relaxation baths. If it does not resolve on its own, seek medical advice as the best way to deal with those problems may be to find the one most suitable for you.

Havin two periods in a month is not uncommon. The cause could be stress or hormonal imbalance. It's generally not dangerous, but consult a DOCTOR if concerned. 

UNWANTED 72 CAN CAUSE PROLONGED BLEEDING.. Consult a doctor.... 

In pregnancy, you may not experience regular periods cycle. It's possible for some individuals to experience bleeding or spotting during early pregnancy, which might be mistaken for a period. This bleeding is often lighter and shorter than a typical period and is known as "implantation bleeding."

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

If you think the symptoms are of pregnancy then you can take a home pregnancy test to confirm, or do a urine pregnancy test.