Is it possible to get pregnant while on hormonal contraceptive implant?

Hello doctor,

I am a 26-year-old female. I am using the Nexplanon contraceptive aid. It was inserted during my period at the time seven months ago. To date, I have had no issues with it apart from mild PMS symptoms occasionally and my periods are non-existent. A week and a half or so ago, I began to feel different.

1. I had a lower back ache constantly and my breasts were very sore.
2. The breast tenderness has persisted and increased as well as they seem fuller and heavier. I am not fitting into my normal bras well.
3. The nipples, in particular, are irritated and sore and extremely sensitive at the moment plus have darkened brown around the edges too.
4. I also am experiencing a lot of fatigue.
5. A heightened sense of smell plus a lot of bloating constantly.
6. Prior to these symptoms beginning, the last date I had sexual intercourse was two weeks roughly. No sex in between at all.

In order to simply rule out pregnancy, I did several home pregnancy tests and received very faint but blue and visible lines within the instructions time frame given. The last four days of testing there was some progression made in terms of how dark the positive lines were and how rapidly they appeared on the test. Naturally, I assume I am pregnant though how I do not know. Worth noting that since just after my last sexual intercourse and still ongoing, I have been suffering from a urinary tract infection and am on antibiotics but have had to extend their duration as it does not seem to be resolving well nor getting worse, however. I began spotting pink blood four days ago which two days later progressed to a period red type bleeding with small clots. This is still ongoing to date but has a tendency to wax and wane. There was an awful amount accompanied by severe cramping and pain for a few hours. The cramps are much milder now and bearable. I am not filling much of a sanitary pad but it is rather when I wipe (aside from the large amount earlier). I assumed a miscarriage, but obviously, I cannot be sure. Now, I still have the same pregnancy-related symptoms. They have not subsided in the slightest since the bleeding began. I am also beginning since yesterday to feel bouts of nausea on and off.

Basically, my query is really three things:

1. Is pregnancy possible?

2. If so, does it seem like an early miscarriage is occurring?

3. Could the urinary tract infection be causing the vaginal bleeding at all?

Notes: I have experienced one previous confirmed miscarriage two years ago. Medications I am currently taking are Dexamphetamine 5 mg, Clonazepam 2 mg as required and antibiotic for UTI.