Not sure ?

Hello to all the lovely ladies using this app, i am a abit suspicious as to weather I could be pregnant or not... And need some help... My boyfriend and I had unprotected sex about a month ago, he didn't actually ejaculate inside of me ... But I have some concerns as to whether I could be still be pregnant due to pre cum .. I have researched all about it and there is actually a small % ladies can still get pregnant due to pre ejaculation ... 
I have experienced symptoms, early stages - 
Sore back and lower stomach when I'm sitting 
More current symptoms- 
Light cramping and nausia feels 
Abdomin pain 
Frequent urination 
Sore throat 
Larger tender boobies 
The start of my last period was the 5th April .. I haven't taken a test yet .... But just need some advise on what to do due to the fact I'm quite young .. Thank you xxx