19mth old and day nap

My DD has for the past two days not had her day nap. She won't settle and stands up in her cot banging around and then cries. I then go put her back down. This happens two ot three times before I give up and just get her up.

Is this a sign she is dropping her day nap or is there something I'm missing. Normally she is really good going down for her nap but now its frustrating the hell out of me as I'm nearly 32weeks preg and when she sleeps is the only downtime I have. if I need a nap this is when I normally have it but if she doesn't sleep i can't have one.

I need help please. What can i do????

 

DS does this some weeks, he started doing it at about 14 months old, when his sister was born, he is now 20 months.

I found that the problem for us was that I was putting him to bed too early, he usually went at 11am, but now he goes to bed at 1pm, and that means he sleeps for the afternoon and I get peace and quiet. He still does play up sometimes and refuse to sleep, but I just leave him in his cot, unless he is hysterical, then I get him up.

I try and have him and DD sleeping at the same time so i can have some down time.

Today he mucked around and cried and got grumpy for about 15 mins then went off to sleep.