Emergen-C accidentally preventing pregnancy?!

I have had a really bad cold that turned into bronchitis. Before I got on antibiotics, I took one packet (containing 1000mg of vitamin C) of Emergen-C on Friday, Saturday, and Sunday. Today is Wednesday, and I started spotting. I'm only 9dpo, and my period isn't due for 4-5 days. I'm always regular & most months I'm 29 days a cycle. If this spotting is the beginning of my period, this would make my cycle this month 25 days, which is unheard of for me.

I was hopeful I conceived this time because we just got back from our honeymoon last week. Could I have ruined it and induced my period when I otherwise might have gotten pregnant? Like if I conceived, did I just accidentally kill it by inducing my period early with those stupid packets that didn't even work? This sucks so much.

Any advice (especially with personal experience) would be helpful.