Did she block me on whatsapp?................help please?

[Dorflant]

We went on a date and it seems to have went well, we even set up a second date for next week. So she is the one who in fact suggested we start chatting on whatsapp. For the past three days we have been having daily short lived convos, not awkward and not really flirty either. So the last text was initiated by her, she evn asked how my day was, but suddenly the next morning her time stamp is stuck on 'last seen yesterday at 23:57' that is around the time we stopped. So at 3 pm I texted her 'hey you ' but I'm surprised because my message is stuck on one check mark, I can see her time stamp and it's active, if she is online I can see but my last message is still on one check mark! I don't understand, we were not even bad terms. I read up on the internet on how to know if someone has blocked you, but I notice the general agreement is that if there is a combination on TWO or more signs, not one. But I only see one sign (the checkmark thing). What could this mean? should I text her again?