2 questions.. sorry if TMI

So this is a 2 part question... first of all I am 5 weeks 5 days and today I wiped and had some dark brown discharge on the toilet paper. Instantly of course I freak out because I have been having bad cramping since I got my BFP. I actually had an ultra sound on Sunday due to some bad cramping.  We saw the gestational sad and it measured 5w/3d. So about right on track but he didn't see much else in there other then a small black spot with he was thinking was the fetus. I have a follow up ultra sound on Monday to make sure everything is going in the right direction. I am a little nervous especially now that I have the brown streaked discharge. Ok now 2nd. DH and I did the deed  tonight for the first time since I got my BFP and it was SO SO dry down there. I had no lube so we had to get creative with a little oral (sorry TMI) to get things a little wet. So I need to go buy some lube just not sure what kind. And of course when I went to the bathroom after andhis stuff was in the toilet there was some dark brown blood in some of it.😳😳