prozac, adderall, and marijuana mix?

Quick paranoid question about safety:

I take 40 mg of Prozac a day but haven't taken more than three in the last two weeks. Yesterday at about 5pm I took a 20 mg Adderall XR. I smoke a pretty good amount of marijuana and still am.

My question is, could serotonin syndrome be a possibility if I take more Adderall or amphetamine-dextroamphetamine (or both) today? I weigh about 145 pounds.

I typically stick to trees, but I love the community here. Thanks all.