pregancy symptoms??

hi Ladies I need some advice... we have been TTC and last Tuesday I had an HSG test. Did BD both before and after. I have a very difficult time trying to figure out when I ovulated so I don't know how many dpo I am. I have been nausea for two days so bad I wish I could make myself get sick just to feel better. around the time I think I ovulated I had diarrhea, then late yesterday and early today I had some dark bleeding and all I do is pee ...but today is only CD13 so I don't know when to do an hpt... Don't want to try too early and disappoint my self...please comment your thoughts and tips