Emotional Rollercoaster Day

So I held out until this morning to do a hpt as I was between 3 & 6 days late (longest & shortest cycles I've had). This makes me cycle day 35. Pretty certain I ovulated on or around Oct 1st which would make me 2-3 weeks pregnant for gestational purposes. I really wanted to use a digital hpt so there was no doubt & I got my BFP just 8 hours ago(YAY!!!!) but was only reading 1-2 weeks. Have had honestly zero symptoms but literally an hour later after husband and I had finished crying, I started getting light pains in my lower abdomen. They're not cramps exactly but actual pains if that makes sense. Shortly after that I went to the toilet & I'm spotting a small amount of brown. Could the fact that my "weeks pregnant" reading was less than I thought be an indication that something is wrong along with these other symptoms now? Sorry for long post but I'm having the best/worst day ever all rolled into one!