Good morning to healthcare magic. You are 29yrs old and missed period of 4days.
If you think of pregnancy
,then you can repeat the urine test after 7-15 days along with a blood test
If both are negative,then you need not to be worried as your previous cycle was regular with 36 days interval.
One thing also keep in mind about OLIGOMENORRHOEA and need to investigate properly.
It is defined as infrequent period and delay of several months in between and more common in pubertal girls.It is mostly due to inadequate maturation of H-P-O axis and inadequate hormonal stimulation.
The cycle are often anovulatory in first 1-2 yrs.Gradually full development of normal ovulatory cycle and it will not have any harmful effect in future fertility
Other causes of Delaying Period:
1)Mental & physical stress like vigorous exercise
nervosa-if wt less than 47kg,mens remain scanty.
4)PCOD with over wt.
So you need to do a USG,Thyroid function test,FSH/LH and prolactin
level if period is irregular or delaying more than 1 month and consult to your gynaecologist.
Along with maintain a healthy diet,control wt and regular light exercise.
All the best. If you need extra consultation,then contact with me,my id: firstname.lastname@example.org