Help 14 weeks

Hi everyone I'm 14 weeks with twins , and I've haven't had any issues so far besides this morning I woke up with dark blood on my underwear so I took a shower and just layed back down to relax a little and try not to stress out , after I got up its now really light blood almost doesn't even look like blood but I guess my question is should I be worried ? Should I go to the ER ? Call my ob ?  Is this normal ? 
Thanks in advance !!