a home pregnancy test is 100% accurate then online testing. so i would say your not pregnant!!
Symptoms don't mean anything. Pregnancy symptoms are the same for numerous other problems and normal things like the start of your period. you can only rely on a home pregnancy test if you took after you missed your period. if you still want to be sure go to your doctor for a blood test.
When is ur lmp? What is online testing?
I'm not the expert myself, but take the home test results over the online results - can you expand on what you mean by an online test? Is it a symptom checker? Home pregnancy test are generally definitive, I can't imagine an online test giving you a confirmable result.
At what stage in your period cycle did you take the home test? Have you already missed your period? If so, the result is not likely to be a false negative and you can probably assume you are not pregnant, since enough time has passed. Take another one just in case. I am not a health expert and I am talking from memory, someone else will be better informed than me.