My girlfriend started her last period on 23 April. She has a regular 24-25 day cycle so she was expecting to have her next period on the 18 May. We had unprotected sex on 1 May and she took a morning after pill on 2 May (the next day). If I have my calculations right she must have ovulated on the 6th. We had unprotected sex again on the 8th and 9th. Now its 23 May and she hasn't had her period yet. Could it be delayed by the Morning after pill she took or she's pregnant. What are the chances she is pregnant and when is the right time to take a pregnancy test.

Hello, I can't say for sure if she's pregnant or what her odds are after taking the morning after pill as these types of things vary from person to person. Yes, there is a higher chance she could be pregnant, particularly if she didn't take the morning after pill or use protection after any sexual contact (namely the last two dates you mentioned).
As far as taking a pregnancy test, she can start taking the test about three weeks or 21 days after the date she had unprotected sex. But, these results may vary from person to person and according to which test she is using. The best way to tell for sure is for her to see her doctor if there's any question after taking the in home tests.

Good luck!

She should wait until about 2 weeks after missing her period (which would be after 6/1) and then she can take an HPT using first morning urine.

Hello, I can't say for sure if she's pregnant or what her odds are after taking the morning after pill as these types of things vary from person to person. Yes, there is a higher chance she could be pregnant, particularly if she didn't take the morning after pill or use protection after any sexual contact (namely the last two dates you mentioned).
As far as taking a pregnancy test, she can start taking the test about three weeks or 21 days after the date she had unprotected sex. But, these results may vary from person to person and according to which test she is using. The best way to tell for sure is for her to see her doctor if there's any question after taking the in home tests.

Good luck!

What if she takes the test within a week of missing her period. Will a positive result be trusted or it might be a false positive?

The accuracy of an HPT increases greatly as time passes from when the period is missed. During the first week the accuracy is less than 50%. But by the end of the second week it goes over 90%

The accuracy of an HPT increases greatly as time passes from when the period is missed. During the first week the accuracy is less than 50%. But by the end of the second week it goes over 90%

Okay thanks. Will wait until next week then.

Will a positive result be trusted or it might be a false positive?

Also to add to Scottgem's advice, false positives can happen due to a 'bad' pregnancy test, certain medications, or even not following the instructions on the box. But, the only way to know for sure is to get an 'official' pregnancy test and examination from a doctor. False positives can be caused from a variety of things, but until it's proven to be negative I think treating it as though she is pregnant and taking the appropriate next medical action is the best way to go.

Okay I couldn't help but wait. She took the test and it came out positive. And I will treat it as positive unless she goes on her periods again.
I'm going to be a daddy... :-)
Scary thought but it will work out for the best... I guess...

Congratulations!

As far as being a parent: Just do your best, that's the best you can do!