Aww, Khigg, I'm sorry about the BFN! Could you maybe have ovulated later than usual this cycle? Maybe that is throwing everything off.
jj, I have to admit I've been very reluctant about having sex since finding out I was pregnant. We DTD for the first time 8 days after the BFP, and it was not the most comfortable, and afterwards I had some pain. Then I had the spotting the next 3 days after that. I don't know that the sex caused the bleeding, but they were kind of associated in my mind and I was afraid to after that. Finally this week I decided to give it another try, but now my husband is reluctant and wants to wait until after our 8 week ultrasound. If we see a healthy heartbeat, then we'll probably try again.
That being said, a lot of women have no problems with it at all! We're just being extra cautious because of what we went through before. From what I read, it's all a matter of personal choice, and you're only recommended to abstain if you have a higher-risk condition, unexplained bleeding, etc.