### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
helloo doctor recently i have been having all the signs of pregnancy but i still have slight periods and pregnancy test comes up negative the same thing happened with my sister and when she went hospital she found out she was 5 month pregnant. is there a possibility i could be pregnant but it just not showing up?

### output:

Hallow Dear, In some occasional cases, some vaginal bleeding may appear around expected menses during pregnancy in first three months. Such bleeding is usually low in amount. In good old days this was labelled as placental sign. In such cases, you have to look for the other symptoms of pregnancy. The cardinal symptoms and signs of pregnancy in first three months are:1. Missing a period. 2. Frequency of urination without burning.3. Nausea & Vomiting with aversion of food taste. More inclination for sour items. 4. Breast signs: They include brownish to blackish discoloration of nipples and areola with increase in the size of areola. Some tubercles (Montgomery's tubercles) appear under the areola. On squeezing, clear secretions or milk may be expressed from the nipples.  The breasts engorge in size rendering the clothes rather tight. Due to engorgement, they become somewhat tender also. 5. After about 6 weeks of pregnancy, urine pregnancy test becomes positive. Earlier it may give false negative results. However, beta Chat Doctor tests, which are very specific and sensitive give reliable results as early as 4 weeks of pregnancy. 6. After six weeks ultrasonography gives direct visual evidence of pregnancy.7. On clinical vaginal examination, the size of the uterus is increased, which is well appreciated after 6 weeks. By this time, the uterus is felt soft. Considering the family history of occasional bleeding during pregnancy, I would advise you to get the status of pregnancy confirmed by reliable method after reliable time. Only symptoms may misguide you. I hope this will help you for proper actions. 