Am I pregnant please help?

I am 15,

My last period was 6th July and lasted 6 days

On the 20th July my boyfriend may have had precum on his fingers when he used them to touch and make contact with the opening of my vagina although he didnt insert any fingers and removed his hand after I reminded him he my have had precum on his fingers

I've been extremely worried that I am pregnant

I had spotting on the 2nd August when I woke up which I've never had before (brown patches that looked like diluted old blood) but this progressed into a normal period however this was very light for me as usually I have verrrrrrry heavy periods that I take tranexamic acid medication for

It is now the 4th and I'm still on my period but still it is lighter than usual (I'm taking the medication anyway)

Today I took a pregnancy test (urine, suresign) it was negative

But I have sore breasts and yesterday I had a metallic taste in my mouth

I've been tired and have suffered from a cold/viral infection for the past week, and loss of appetite/nausea

My period is now lighter than usual although it's still a period flow could this be because Ive been stressed? What about all the pregnancy symptoms? I'm scared cause I've heard people bleed and have negative tests but later find out they are pregnant

I am also worried because I was probably ovulating on the day (20th July) precum old have entered my vagina (tmi sorry)