Hi. I have a 13 day luteal phase. I started spotting at what I believe is 13 dpo, which is unusual for me.

( Im basing dpo on my ovulation pain. The 4 months I charted I always ovulated the day after ovulation pain. ovulation is usually the 16 or 17th day of my cycle ) . Spotting is not usual for me. The next day I started bleeding but very lightly with little to no clotting and it only lasted 2 days followed by 2 more days of spotting. I'm normally very heavy and period usually lasts 6 days. I have taken many pregnancy tests but all have been negative so I'm guessing I'm not pregnant although I feel like I am. (unless there is some reason I'm getting false negatives which I have read is unlikely.) I guess I should add that my husband and I have been actively trying for 7 months and had intercourse around my fertile window. I guess the reason I'm writing this is I can't fight the feeling that I may be pregnant and I don't want to drink tonight ( going to a cocktail party with friends) if there is a chance I am. I took a test this morning at 19 dpo (if that wasn't a period) and it was negative. So there is no chance right?? The last time I had my blood drawn she said my thyroid levels were borderline but that I wasn't quite at the levels of hypothyroidism so it's mostly likely a hormonal imbalance I'm guessing?