Sorry for asking this...but Implantation bleeding is real, right?

I had positive OPK 5/3 PM on one of the Internet cheapies and then solid smiley 5/4 AM with FMU with Clearblue Adv. Digital. I had some weird pelvic pressure- it almost felt like I held my pee for too long and that soreness/pressure you feel in your bladder after you use the bathroom and what I thought was slight tingling on my nipples. Then I had brown spotting for literally a day 5/9 where I had to wear a liner. Since then...no symptoms. If I think about it, I feel like my nipples feel funny but I’m not sure if that’s me thinking about it. I don’t think I’ve ever paid this much attention on how my nipples felt before in my life! 🙃

I have PCOS, TTC#1, and this is my second cycle of back to back Femara 2.5 to 5mg. So, to say I don’t really know what’s going on with my body right now is an understatement.

I got my progesterone labs drawn on Friday but it didn’t result before the clinic closed so guess I won’t know until Monday.

I know TWW still applies so I’m trying to put off testing but anybody with similar experience..? Or some insight?

If it WAS implantation bleeding...when’s the earliest I can test..?!