Periods - is this normal ?

I’m posting this on a few groups because I really would like advice! So I was supposed to start my period on the 14th of June. I was stressed beforehand because I was genuinely scared of the fact that I could be pregnant simply because I’d been feeling really strange during the month and I had unprotected sex with my boyfriend. It wasn’t near my ovulation date but still - it was stupid. My discharge was always slightly different during the month - it was dry on some days and thick on others, and I thought it could’ve been because I was stressing because of the fear I could be pregnant. Anyways, I got my period on the 14th which was a relief to me because I had been stressing. However, it was really light, brown spotting instead of the usual period. I didn’t think much of it because at the beginning of my periods, it’s usually very light and spotty but this continued onto the 15th. I went with my boyfriend to take a pregnancy test as I thought it could be implantation bleeding and it came out negative on the 15th. The next day, my flow was heavy and I had severe cramps which is normal for my period. This was on the 16th. My periods are usually heavy for the first three days and then are light however today (which should be the 6th/4th day, depending on whether you think it started on the 14th or 16th) it was very very heavy. I’m worried about what it is - has anyone had anything like this? Am I just overreacting and overt thinking? Please offer any advice