The answer is straight. You may be pregnant again.
Please do a urine pregnancy
test as soon as possible to confirm it and proceed further.
Use a regular contraceptive pill until the time your cycles become regular. Take a wise decision always.
If pregnancy is ruled out, then we need to look at other causes of delayed periods. In both cases going on regular oral contraceptive pills
will help you.
I hope to have been of some help to you.
Wish you good health.