Help? Normal bleeding? Birth Control cause?

Ok so I’ve been on nexplanon for roughly 2.5 years.. In July (we stopped having sex June) a guy I was seeing told me to get tested for an STD it came back positive for Chlamydia, I had symptoms but I didn’t know at the time, it was after the positive test it made sense. Well I started dating a new guy the middle of July, didn’t know anything about the STD possibility. We slept together, unprotected a few times then I got the results I was devastated and I told him. He hasn’t gotten tested cause his insurance hasn’t kicked in. I don’t have symptoms so I haven’t retested yet. I’m going to! My question is I think I’ve started my period but I’m also very paranoid and unsure if it’s even really a period. Feels and acts like one. Bled normally in September. October 13th I started and stopped on the 20th. And now today I have light brown spotting. I’ve been reading the bleeding is normal around this time with the nexplanon. Anyone have any ideas? And yes I am getting retested, I’m waiting on my appointment. Also how long until Chlamydia causes PID? No pain during or after sex or bleeding afterwards (main symptom when I first found out) is it possible I had it and he hadn’t contracted it? I took my dosage and didn’t have sex with him for a week. But we had sex like 3 times before I got the result..