Withdrawal or breakthrough bleeding?

I've been on Trinessa for several months, and then I missed two days after my last pack (after the 7 inactive pills).  I started taking the new pack two days late, and then three days into it, I was put on the antibiotic doxycycline.  That antibiotic made me sick so I was put on Augmentin.  In the past couple of days, the dose of Augmentin was increased. (I have been on antibiotics for 3 weeks now) Now I'm experiencing some light bleeding when I wipe, it started off barely visible and pink, but after intercourse it was a little heavier and brown (still only when I wipe.)  I have 4 more active pills before the inactive ones.  Am I experiencing withdrawal bleeding due to the antibiotic or could it be implantation bleeding?

[anon807]

I also meant to mention that for the past few days I've been having hot flashes and heartburn, and I've been really tired (let's just say I'm about 30 years away from worrying about menopause)