Clopidogrel and bone graft interaction?

I grafted LR4-6 after teeth extraction. I used bovine bone graft, collagen membrane and prf membranes. Healing was uneventful. Monitoring the pt every week after the surgery everything looked good. Primary closure achieved, minor swelling etc. One month after the surgery the pt took a single clopidogrel dose. 2 hours after the medication the pt experienced some short of swelling at the grafted area. Saw the pt next morning and the patient had moderate swelling, no pus, the graft are was intact. Prescribed antibiotics and the swelling subsided. Pt discontinued clopidogrel. Do u think it’s a coincidence or some short of interaction of the medication?