Gestation Calculator

This calculator has been designed to give you an idea of the treatment options available to you*. If you decide to have an abortion with Marie Stopes UK, one of our nurses will give a more approximate gestation date during your appointment by way of a scan.
*Please note that this online calculator will only give you an estimated gestation based on the details you have provided.

Please select the first day of your last menstrual period.



We are here to support you 24 hours a day, 7 days a week

Call us now on 0345 300 8090 or email services@mariestopes.org.uk

0345 300 8090

You are here


HIV (Human immunodeficiency virus) is an infection that attacks the immune system. This reduces the body’s ability to fight off infections. Without treatment, a person with HIV will stop being able to fight off certain infections and cancers and this stage of HIV is called AIDS (Acquired Immune Deficiency Syndrome).

How do I get HIV?

There are three main ways of getting HIV:

  • having unprotected vaginal, anal or oral sex with an infected person
  • blood to blood: eg, sharing needles/syringes
  • from an infected woman to her baby during pregnancy, child birth or breastfeeding.

How do I know if I have HIV?

When people are initially infected with HIV, they can develop flu-like symptoms such as headache/tiredness/muscle aches and a rash. Some people do not develop symptoms at all. People can then go for a period of time without experiencing any symptoms at all which means they can pass the illness on to their partner without knowing they have it.

As the virus continues to attack the immune system without treatment, people can develop symptoms such as constant tiredness, swollen glands, sweats at night, memory loss, diarrhoea and weight loss. When the immune system is badly damaged, the body is susceptible to other serious infections and cancers, and this is called AIDS.

The only way to know if you have HIV is to visit your doctor and have a blood test. As there is about a 3 month period after which it may not show up on the test after exposure, you may need to have the test repeated after 3 months. At Marie Stopes, we offer confidential and fast HIV testing. 

How do I get treated for HIV?

There is no cure for HIV, but there are several treatments available which allow people with HIV to live well for many years with treatment. Pregnant women must be treated for HIV to prevent their babies from becoming infected with the condition. If you have HIV, the doctor will ask you about contract tracing so that people who may have been exposed through you can be tested. 

What would happen if I didn't get treated for HIV?

HIV will continue to attack your immune system, which means you will be more susceptible to serious infections and cancers. AIDS can lead to death and permanent disability. 

How can I prevent myself from getting HIV?

There is currently no vaccine for HIV.

You can protect yourself from exposure to HIV if you follow this advice:

  • Don’t share needles/syringes or any drug injecting material.
  • Practice ‘safe sex’ using condoms and damns.
  • Don’t share personal hygiene items like toothbrushes, razors and dental floss.
  • Discuss STIs with your partner, even when it is difficult to talk about. Your partner will appreciate your honesty and that you don’t want to infect him/her. You have the right to know if they are infected too. Talking about HIV can be difficult, but if you are HIV-positive you must talk to your partner before you have sex.