IS IT IMPOSSIBLE TO BE PREGNANT? !

I'm a 19 years old and would hate to be pregnant right now.

I have been on Nexplanon since March and have not had a period since.

My boyfriend and I use condoms and one broke probably around 4 to 5 weeks ago .

I got STD tested and he did too and we are both still clean.

Is it impossible for me to be pregnant?

Or get pregnant? He did ejaculate in me.

Does it even pay to take a pregnancy test or is it a 100% no?

Thanks much!

I have been getting really bad headaches the past week as well, and the last headache I got was probably 3 years ago. I have also had some cramping and I never have cramping. Just a bit yesterday. I have also been nauseous for the past 16 days.

Are these credentials something that tells me I should test?

I am with family for a week 2 hours from any store and there is only a small gas station and hotel, in which both do not have pregnancy tests so cannot pick up a test at the moment..