Hello Dear,
Since you took the pill on April 9th, it would not protect you till April 15th. So the unprotected intercourse can result in pregnancy. The pregnancy test may give a false negative result. There is also a possibility that you may not be pregnant and your mensus are not coming because of some other reason.
The best way to confirm is to go to a doctor and get a ultrasonography of abdomen done.
The symptoms that you have mentioned are not very specific for pregnancy, so nothing can be said for sure.
Hope for the best.
Dr Juhi

Hello, I would be happy to help you today.

I will make the assumption that you have regular 28 day cycles in terms of my answer. Based on this assumption, you were most fertile around April 14th.

So it sounds like you probably had unprotected intercourse during the first half of your cycle, and then took PlanB on April 9th. Then, you had unprotected intercourse on April 15th right around when you were most fertile. The only difference in this case is that PlanB tends to delay ovulation in terms of when you took it during your cycle. So, the possibilites include:

1. You are pregnant
2. You are not pregnant and late because ovulation was delayed by the PlanB (most likely)
3. You symptoms are most likely related to your cycle

Given your negative testing in May when i would have expected it to be positive, I am guessing you are not pregnant. Given the confusion with regard to your cycle and potential conception, I would have someone like you repeat it weekly for 2 additional weeks beyond when you thought your period would come.

I hope this helps!!