Pregnant? Or not 😫

Shannon🎀
Ok so I'm on the implant. So I've thought there's no way I'm pregnant, but I've started getting loads of symptoms 
Really sore/ sensitive boobs
Cramps 
Nausea 
Change in appetite 
If I was pregnant I know that I would of conceived on the 30th of Jan. It's the only possible time I could of got pregnant. I've tried a pregnancy test its negative but it was £2 so might not be accurate. Would I be too early to test positive? Or am I thinking too much about itÂ